Stock exchange regulation and the official price lists of the stock exchanges of Brussels and Antwerp, 1801–1935

To fully understand and exploit the contents of stock exchange official price lists, an in-depth knowledge of local stock exchange regulations and practices is required. This article offers a comparative perspective on price discovery and quotation on the two most important Belgian stock exchanges, Brussels and Antwerp, from their establishment in 1801 up to the reform of 1935.

Regular publication of prices of securities admitted to trading on an exchange by an officially recognised body served two purposes: verification and information. It was a means for principals to check the execution of their order by an intermediary (Limauge , p. ; Bastiné , pp. -). It also informed investors about the state of the market. Over time, stock exchanges therefore began including additional information in their price lists. The official price list of the Brussels Stock Exchange was regarded by contemporary observers as one of the most complete in this respect (Thiebauld , p. ). Securities were organised by type and by industry in this list. For bonds, details about the interest rate and ex coupon date were included from the beginning. By , the list included not only prices, but also details on the last dividend and the initial and outstanding amount of an issue. Later, individual tax rates for corporate bonds and a flag for the existence of multiple voting shares were included (see Table ). The official price list of Antwerp, Belgium's second and less comprehensive market, offered similar additional information. Other data, such as traded volumes or corporate actions (for instance, stock splits and reverse splits), were not published in the price lists but can be found in secondary sources.
By publishing all those data the Brussels and Antwerp stock exchanges exhibited a high degree of ex-post transparency. Annaert et al. (, ) collected high-quality micro-data from these price lists to produce homogeneous long-term time series of returns on Belgian stocks. Little is known, however, about the process of price discovery and ex-ante transparency in these markets. How were buy and sell orders matched? How was information about orders disseminated? Who quoted prices? And how did this affect the publication of price quotes in the official list? We investigate these topics against the background of changes in regulation, differentiating between a regulated and an unregulated period separated by the liberal reform of . Moreover, we contrast Brussels with Antwerp, because the market dynamics of these two exchanges diverged in terms of the importance of the securities trade vis-à-vis commercial transactions and the types of securities listed.
The remainder of this article is structured as follows. The second section describes Belgium's legal framework for the organisation of exchanges. Price discovery and the quotation and publication of prices before and after the reform of  up to the next reform of  are the subject of the third and fourth sections respectively. The final section concludes.

II
The discovery and quotation of prices and the contents of the official list cannot be understood without understanding how exchanges were organised in Belgium during the period under study. Initially they resembled very much the French exchanges' organisation. In , Napoleon introduced the first legislation on the organisation of exchanges (bourses de commerce) in the French Empire. The Napoleonic legislation was partly based on earlier regulations which were directed exclusively at the Paris Bourse, but it also introduced new elements. Bearing in S T O C K E X C H A N G E R E G U L AT I O N A N D O F F I C I A L P R I C E L I S T S  mind the collapse of John Law's system in  and the more recent speculative boom of the s, successive French governments regarded regulation of exchanges as an appropriate reaction to wanton speculation or agiotage. These regulations were consolidated in Title V of the  Code de Commerce which came into effect in the French Empire, including the Belgian départements, on  January . Together, the  (Bastiné , pp. -). The exchanges of Brussels and Antwerp were established by the decrees of  and  Messidor year IX ( and  July ) respectively (Mollot , pp. -). However, the implementation of the aforementioned law by the decree of  Germinal year IX ( April ) left the keeping of the order at the exchange to the local authorities who could, subject to the préfet's approval, issue policing regulations. A special police commissioner and the representative organisation of stockbrokers (Chambre syndicale), composed of a president (syndic) and six deputies (adjoints) elected by and from the ranks of the brokers, were charged with overseeing the observance of the law and regulations (Bastiné , pp. -). Article  of the Code de Commerce confirmed that exchanges could only function with government consent and under government supervision (Bastiné , pp. -). During the Dutch King William I's rule over the Belgian territories (-), the government temporarily retreated from its supervisory task. The appointment of brokers, for instance, was left to the local authorities (Willems and Buelens , pp. -). After gaining its independence in , the young Belgian state again asserted its control over the exchanges. During the first  years of Belgium's existence, the Catholic and Liberal parties, united in their opposition against William I since , frequently governed in coalition. Notwithstanding the liberal constitution of , the economic policy of these so-called unionist governments was rather conservative. Barthélemy de Theux de Meylandt, for instance, Interior Minister for the Catholic Party between  and , drafted the legal framework in which the Belgian exchanges would function until . As a representative of the landed elite, he was a firm opponent of financial capitalism and advocate of firm controls. The royal decree of  April  instructed the local authorities to draft policing regulations for their respective exchanges and have them approved by the government (Mollot , pp. -). De Theux's Liberal successor Charles Liedts (-) continued in a similar vein. During his tenure, the government invoked its supervisory authority to regulate the admission of securities to the official list. Whereas the French government entrusted the Chambres syndicales to decide which securities could be quoted, the royal decree of  November  subjected the official listing of securities to government approval. This measure formed part of a comprehensive policy, including a more stringent regulation for joint-stock company incorporation in February , which aimed to increase investor protection (Mollot , pp. -; Stevens ; Willems and Buelens , pp. -, -).
Brokers had long held a monopoly on intermediating transactions. Both the law of  and the decree of  had already distinguished between commercial brokers (courtiers de commerce) and stockbrokers (agents de change), however, without describing S T O C K E X C H A N G E R E G U L AT I O N A N D O F F I C I A L P R I C E L I S T S  their respective competences in detail. This was clarified in the decree of  Prairial year X ( June ). Article  stipulated that it was forbidden to buy or sell securities without the intermediation of a stockbroker. Moreover, all securities transactions had to be effected inside the exchange building and during exchange hours. It hence put those transactions within the exclusive competence of stockbrokers and within the confines of the exchange (Bastiné , pp. -). The stockbroker's monopoly was confirmed by the Code de Commerce, which also described extensively which activities the commercial brokers could engage in. The monopoly enjoyed by the stockbrokers was more comprehensive than that of their colleagues. Whereas merchants could trade bills in their own name or to bearer as well as trade their own goods amongst themselves directly, no securities could legally change hands without stockbroker intervention.
In return for the privileges they enjoyed, brokers had long since had to meet a series of strict requirements. They had to have experience in trade or finance, for instance, and could not engage in the securities trade or in any other kind of commercial or banking operation on their own account, nor in any business firm. Brokers also had to put up a large sum of money as surety against default. These old requirements were confirmed by the law of  and the decree of . The law of  further added in article  that only government-appointed brokers could exercise the profession. Their numbers were fixed by decree. In Antwerp, there could be no more than  agents de change and up to  courtiers de commerce. In Brussels,  brokers could combine both functions (Mollot , pp. -). This was confirmed by the Code de Commerce (art. ). During the Dutch era, the appointment of brokers was temporarily left to the local authorities. With the aforementioned royal decree of  April , the young Belgian government again seized the prerogative to appoint brokers and subject candidates to a test. From ,  stockbrokers were permitted to be active in Brussels; this was raised to  in  (Willems and Buelens , pp. , ).
The law of  December  completely broke with these principles and liberalised the Belgian exchanges (Bastiné , pp. -; Willems and Buelens , pp. -; Buelens et al. ). This law was part of a series of reforms by the Liberal governments of Charles Rogier (-) and Walthère Frère-Orban (-) to strengthen economic liberalism in Belgium. Under their tenure, laissez faire replaced interventionism in economic policy: the liberalisation of exchanges was preceded by the abolition of municipal excise duties in , free-trade agreements with France (), the United Kingdom () and the German Zollverein (), and the removal of interest rate caps in . In , moreover, government approval for the incorporation of joint-stock companies was scrapped. Prefiguring this policy change, the last Unionist government had responded to increasing complaints from the local authorities in Antwerp and Brussels about the inadequacy of the regulation of exchanges by appointing, in , a parliamentary commission to prepare a reform (Vanthemsche a, pp. -; Willems and Buelens , pp. -).
By then the regulation of the stockbrokers' profession and admission of securities to the official list was circumvented by moonlighting brokers who traded popular but  not officially listed securities in coffeehouses such as the Lloyd bruxellois (Willems and Buelens , pp. -). However, the principle that exchanges could only be established and function with permission and under supervision of the government was also deemed at odds with the constitutional liberty of association and therefore abandoned, opening the establishment of exchanges to private initiative. Everybody could freely and without intervention from the authorities set up an exchange. The government also no longer decided which securities could be admitted to the official list. The municipal authorities, however, remained in charge of keeping order on the exchange. Since the Brussels and Antwerp exchanges were accommodated in municipal buildings, the local authorities by rights intervened in the organisation of the exchange too. Until the reform of , the Brussels and Antwerp municipal councils would continue to issue organisational regulations, including listing requirements and instructions on how prices were to be quoted.
The profession of broker was also liberalised. Appointment by the government or the local authorities was no longer necessary. Payment of the trade tax (droit de patente) was the only remaining requisite for exercising the profession. In Antwerp and Brussels, this tax ranged from  to  BEF, depending on the importance of the business. The local authorities in Brussels, however, also subjected entry to the official trading floor ( parquet) to an annual tax of  BEF in  (raised to  BEF in ). Antwerp introduced a similar annual tax of  BEF for entry to the parquet after the securities trade moved into its own building in  (Gemeenteblad , p. ).
The stockbrokers' monopoly on trading securities was also abolished. Everybody could freely trade securities inside or outside the exchange. In turn, stockbrokers were also allowed to trade on their own account. The Chambres syndicales, finally, were replaced by Exchange Commissions. These commissions consisted of  to  members appointed for three years by the local authorities, after consulting the Chamber of Commerce and the Commercial Court. Each year, one-third of the commission was renewed and former members could only be reappointed after an interval of one year. After the Chambers of Commerce had been abolished in , the Commercial Courts continued to appoint the Exchange Commissions together with the stockbrokers. This practice was legalised by the law of  June  adopted during the second Frère-Orban government (-).
Faithful to its liberal principles, his government did not respond to demands by a group of stockbrokers to reinstate stringent requirements for exercising the profession (Vanthemsche a, pp. -; Willems and Buelens , pp. -). These demands resurfaced during the crises of the early s and resulted in the appointment of a commission by the Catholic government in . In its final report, published in , the commission recommended reregulation, but its recommendations went unheeded, close ties with the financial elite preventing the conservative Catholic Party from intervening in the stock exchange. A continuing series of financial scandals and a new generation of more progressive Catholics by  revived the appetite for regulation. The first regulation of prospectuses and accounting by jointstock companies was introduced in , but stock exchange reform was thwarted by  the outbreak of World War I. In , the national unity government of Liberals, Catholics and Socialists finally passed a bill that put the stock exchanges under the supervision of the Minister of Finance.
The law of  March , amongst other things, subjected the listing of foreign securities to preliminary approval. It was meant to herald more comprehensive regulation, but the fall of the last national unity government prevented a bill introduced to this end in  from being adopted. In subsequent governments, consisting of Catholics and Liberals, the position of Minister of Finance was without interruption occupied by men with very close ties to banks, who left the liberal principles of the law of  in place until the reform of  (Vanthemsche b, pp. -; Matheve , pp. -).

III
With regard to quoting securities' prices, the French legislator had vested extensive powers in the brokers and their organisations. The aforementioned law of  Ventôse year IX stipulated that only commercial brokers and stockbrokers appointed by the government could quote exchange rates and the price of securities, commodities, and gold and silver (art. ). The decree of  Prairial year X contained more detailed provisions on the price discovery system for securities at the Paris Bourse (art. -). It reinstated the open outcry (criée) which guaranteed both ex-ante and ex-post transparency. Stockbrokers gathered on the parquet, an enclosure in the centre of the exchange accessible only by stockbrokers, to shout bid and ask prices for securities (effets publics et particuliers). If orders matched, they announced the price to the caller (crieur), who immediately called it out loud if the transaction involved sovereign bonds (effets publics). Prices of corporate shares (actions de commerce) and bills of exchange were collected by the Chambre syndicale and quoted on the price list after the closing of trade (Locré , vol The earliest regulations of the Brussels and Antwerp exchanges were far less detailed in this respect, however. At the time, both were principally commercial exchanges. Financial transactions mainly involved trading bills of exchange. A limited securities trade existed only in Antwerp (Locré , vol. , pp. -; Willems and Buelens , pp. -, -). An extensive regulation of price discovery, as in Paris, was therefore superfluous and the legislator also considered trading bills of exchange to require less public scrutiny than securities transactions. The regulations laid down by the aforementioned decree of  Prairial year X for the Paris Bourse were very explicit in this respect: the negotiation of bills of exchange required deliberation and consideration and could not be effected in a loud voice. Their prices were collected after the exchange, by the Chambre syndicale, and quoted in the price lists (Locré , pp. -).
The regulations for Brussels and Antwerp also stipulated that the brokers were jointly responsible for quoting prices after trading had ended (Mollot , p In Brussels, from , the syndic and his two adjoints quoted the exchange rates on Tuesday and Friday. They had to affix these rates the next day before noon at the exchange and could also distribute them in printed form. The price of securities, commercial paper, precious metals and commodities were jointly quoted by the Chambre syndicale and the brokers (Limauge , pp. -). 2 This was also the case in Antwerp. The regulation of  dictated that the stockbrokers gathered in their usual place at the exchange at : on Monday, Thursday and Saturday for quoting exchange rates and the prices of securities. All stockbrokers who visited the exchange on a day when quotations were fixed were obliged to participate and absence was fined. Quotations were determined by majority vote, annotated in a special register, signed by the syndic and printed (Réglemens général et particulier , pp. , -). 3 Following the aforementioned royal decree of , new exchange regulations were approved by royal decree on  December  with effect from  February . For the first time the regulations regarding price discovery and quotations showed a divergence between the Brussels and Antwerp exchanges, reflecting incipient differences in the relative importance of the securities trade and the type of securities traded there. Following Belgian independence, Brussels firmly established itself as the primary market for securities. During the s, Brussels-based universal banks floated industrial securities from Walloon industrial enterprises under their control on the Brussels exchange (Chlepner , pp. -; Willems and Buelens , pp. -; Ugolini ). In , after the first industrial boom (-) had ended,  out of  securities on the Brussel's official list were actions industrielles et commerciales (Mollot , p. ). 4 The Antwerp exchange remained primarily a commercial exchange with a secondary market for sovereign bonds. In  its official list counted  listings, of which  were foreign debt issues and only  corporate securities (Mollot , p. ). 5 2 Ordonnance concernant les agents de change et les courtiers de commerce de la ville de Bruxelles,  Jun. . 3 Réglement pour le corps des courtiers de la ville d'Anvers,  Sep.  (art. ) and Réglement particulier pour la Chambre syndicale des courtiers près de la Bourse d'Anvers,  Jul.  (art. -). 4 Liste des fonds publics admis à la cote officielle près la bourse de Bruxelles, publiée en execution de l'arrêté royal du  novembre . 5 Liste des fonds publics admis à la cote officielle près la bourse de Anvers, publiée en execution de l'arrêté royal du  novembre .


In Brussels, the new organisational regulations of the  decree introduced ex-ante and ex-post transparency (Mollot , pp. -; Limauge , vol. , pp. -, -; Willems and Buelens , pp. -). This began with the installation of the parquet, a central enclosure accessible only to official stockbrokers so that they would not be confused in the crowd that flocked to the exchange and individuals could find them more easily. 6 The  regulations also stipulated call auction trading. At :, the stockbrokers entered the parquet for trading and quoting the prices of securities. A stock exchange official, the crieur public, called out the securities on the official list one by one. When a security was called, the stockbrokers could shout their buy and sell orders. If this resulted in a transaction, the crieur immediately called the price and marked it in a special register. If supply and demand failed to meet, bid and ask offers (cours papier and cours argent) were quoted. The proposed price quotes were not finalised until after a sufficiently long break to allow the public present to give a parquet member divergent buy or sell orders. At :, the stockbrokers left the parquet and the quotations were affixed in the exchange. No fundamental changes were introduced in this field before the deregulation of  (Limauge , vol. , pp. -, -, -).
By contrast, Antwerp more or less continued the old method of quoting prices. The  decree made the Chambre syndicale responsible (Mollot , pp. -; Ministère des Finances , p. ). Together with four stockbrokers rotating on a monthly schedule, the chamber met after the closing of the exchange to fix exchange rates and securities prices. As per the Code de Commerce, they could only fix prices according to the transactions made in the exchange during hours and is was explicitly forbidden to effect transactions within the chamber. The price list was to be affixed in the exchange building and delivered to various authorities. According to Limauge (, vol. , p. ), Antwerp's nontransparent method of quoting prices privately by the Chambre syndicale often gave rise to errors and complaints. The government also repeatedly protested against the lack of order and price transparency inherent to Antwerp's hushed voice trade. The criée was regarded as beneficial and essential for the protection of investors, but the Chamber of Commerce defended the Antwerp custom in the interest of the commodities trade. Later requests by the stockbrokers to improve ex-ante and ex-post transparency by installing a parquet in the exchange were also blocked by the commercial brokers who called the shots at the exchange and had the Chamber of Commerce's backing. The latter's argument was that open outcry would disturb and disrupt commercial dealings. Only in  did the Antwerp exchange dedicate an enclosure (corbeille) to trading securities (Willems and Buelens , pp. -, ). 6 The nineteenth-century parquet is not to be confused with the later 'floor market' (Parketmarkt in Dutch).

IV
The law of  December  reaffirmed the principle that quotations ought to be the outcome of negotiations and transactions effected at the exchange (art. ).
Prices were no longer jointly quoted by the stockbrokers, however, but by the aforementioned Exchange Commissions. Local regulations were to set the process of price discovery and quotation by the Exchange Commissions. Hence, the authority to draw regulations for the official list was delegated to the local authorities (Bastiné , pp. -, -). As owners of the exchange buildings, the municipal authorities of Brussels and Antwerp drew new organisational regulations for their exchanges. In Brussels, provisional regulations for the Exchange Commission of  January  (L'Independance belge,  Jan. , p. ) abolished the call auction. Stockbrokers could now trade continuously. Between : and :, they could declare the prices of their transactions. At :, three Exchange Commission members drew up the official list based on these declarations. They could investigate and, if need be, dismiss spurious prices, as well as quote undeclared prices ex officio. Then, the price list (cote) was affixed in the exchange building in clear public view. Only cours faits were quoted on the price list, however. The quotation of bid and ask prices was discontinued, albeit temporarily.
In the ensuing municipal council debate the liberal mayor Jules Anspach showed himself to be in favour of deregulation. He defended the abolition of the call auction (criée) by the bench of aldermen. According to the mayor, the criée, whereby securities were called up one by one in the order of the official list and stockbrokers announced their orders in a loud voice, slowed down business, whereas the new system offered full liberty to effect transactions in all securities at any time. The mayor's opponents, however, argued that the criée offered better guarantees to the public and presented buyers and sellers with an easy way of assuring themselves of the sincerity of the prices quoted. Their arguments notwithstanding, the abolition of the criée was definitive, but the publication of bid and ask quotes was reintroduced on  February  to allow the public to avail itself of the state of the market in securities for which no cours faits were quoted (Bulletin communal , pp. -, -; Willems and Buelens , pp. -). The updated regulations stipulated that, during the aforementioned period, stockbrokers could also declare prices for current buy and sell orders in securities that had already been traded. From :, stockbrokers could post bid and ask prices for securities that had not been traded. Bid and ask prices were displayed publicly in the exchange until : and included in the price list alongside the cours faits.
By contrast, in Antwerp the  reform did not significantly alter the way in which quotations were fixed. After the exchange had moved to its new building in , three Exchange Commission members quoted prices jointly with stockbrokers S T O C K E X C H A N G E R E G U L AT I O N A N D O F F I C I A L P R I C E L I S T S  paying the municipal tax for visiting the exchange. 7 For securities, the lowest, highest and closing prices were published in the official price list. If the latter was a bid or an ask price, this was indicated with the letters A or P (Bozérian , p. ).
After the Brussels Exchange had moved to the new Bourse Palace, the organisational regulations of  May  came into effect (Bulletin communal , pp. -; Bastiné , pp. -; Guillard , pp. -). The principle was maintained that only prices of cash transactions (au comptant) were quoted when effected by the intervention of stockbrokers between certain hours on the parquet. However, no price could be quoted for small transactions involving less than ten securities with a par value below , BEF or less than five securities with a par value of at least , BEF, unless the Exchange Commission decided otherwise. All prices of transactions involving at least , BEF were quoted regardless. 8 Internal regulations set further modalities for price discovery. By  the effects of the  liberalisation were already apparent, the number of stockbrokers and securities on the official list having risen from  to  and  to  respectively. To facilitate finding a counterparty, the Exchange Commission deposited special sheets with pre-printed names of securities flanked by columns for bid and ask prices on desks on the parquet at :. Until :, stockbrokers could record their buy and sell orders in the designated columns. Until :, they could also submit prices of transactions at fixed limits by means of index cards to an exchange employee (coteur) who would enter them in a special register. At :, two Exchange Commission members verified the cours faits, quoted prices that had not been submitted, rejected spurious prices, and quoted bid and ask prices. Immediately afterwards, the price list was affixed in the exchange and printed. 9 To further inform the public about the state of the market in a security, a column with the last quoted price, which could be a bid or an ask price, was added to the official price list in .
In , controversy emerged over the publication of bid and ask prices in Brussels' official list. The Exchange Commission had abolished their publication in November  and at the same time substituted the aforementioned last quoted price with the last cours moyen, the arithmetic average between the lowest and highest cours faits (Colinet , pp. -). Their suppression was confirmed in the new organisational regulations of  December . During the discussion in the municipal council, supporters of the proposal argued that the publication of bid and ask prices presented room for fraud and errors, whereas its opponents countered that their absence deprived investors of knowing the potential value of their securities and of the 7 The list of stockbrokers subject to this tax was made up annually by a commission composed of representatives from the municipal council and the Exchange Commission (Willems and Buelens , p. ). 8 These limits were raised, after World War I, to  securities and , BEF respectively (François , pp. -; François-Marsal , p. ). 9 These principles were unaltered by the organisational regulations of  Nov. ,  Dec.  and  Mar. . The abolition of bid and ask prices remained controversial for many years to come. In August  councilman Wauwermans argued that the absence of bid and ask prices enabled shrewd stockbrokers to abuse previous prices published to sell securities to unsuspecting provincial investors at inflated prices (Bulletin communal , pp. -). Similar concerns were voiced by Colinet (, pp. -), who judged that the Exchange Commission's answer to these unscrupulous practices, resolved in November , was half-baked. Their solution consisted of allowing stockbrokers to propose in the price list a price at which they would buy or sell between sessions (a so-called cours modifié). If a counterparty presented itself before the start of the next session, this price was included in the last price column. The price lists did not explicitly mention that the cours modifié was a bid or an ask offer, however, so inexperienced investors could, according to Colinet, still mistake it for a cours fait.
Detailed price discovery regulations for the Antwerp exchange were issued only after the growth of the securities trade during the last quarter of the nineteenth century had warranted the establishment of a separate stock exchange in  (Gemeenteblad , pp. -). By then Antwerp had firmly established itself as the principal Belgian market for foreign government bonds. This necessitated better regulation of price discovery and quotations and the organisational regulations of  provided exactly that (Ministère des Finances , pp. -). These mirrored the aforementioned regulations introduced in Brussels in . The organisational regulations of  March  subsequently transformed the sheets for recording buy and sell orders into a limit order book as it introduced rules for price priority. Prices which were lower than a bid price (cours argent) or higher than an ask price (cours papier) previously recorded on the aforementioned sheets could not be quoted. The use of the order book was strongly encouraged by the rule that complaints from stockbrokers against a price quoted by another stockbroker were only admissible if their order was duly recorded. Penalties for not reporting cours faits were also introduced (Règlement d'ordre intérieur , pp. -). No such obligation existed in Brussels, however (de Reynrode , p. ).
After World War I, price formation on the Brussels Stock Exchange was deeply affected by liquidity constraints consequent on the number of listed securities growing. In , the official list contained  securities; in , , and by , , (François-Marsal , p. ; Lamal , pp. -). The situation was aggravated further by the practice of settling orders outside the exchange. In , two judgements by the Commercial Court in Brussels and the Court of Appeal in Liège had confirmed settling orders 'par application' (literally 'by employment') was legal. Hence, stockbrokers who received opposing buy and sell orders from clients could match them outside the exchange. By the interwar period, banks would also typically try to clear stock market orders received internally. To this end the Société Générale, for instance, centralised all stock market orders from its S T O C K E X C H A N G E R E G U L AT I O N A N D O F F I C I A L P R I C E L I S T S   branches. This further reduced the number of orders taken to the exchange (Colinet , pp. -; Tienrien , pp. -; van der Valk , p. ; Brassine , p. ; Vanthemsche b, pp. -). Hence, Lamal ( pp. -) estimated in  that 'a broad, vivid and regular market' existed for only  out of , domestic securities on the official list. Another  were 'more or less actively traded'. Together, these securities totalled  per cent of the market capitalisation and an estimated  per cent of transactions.
During the interwar period, a dual method of price formation based on liquidity developed in Brussels. Actively traded securities were traded in small groups (en groupe) of stockbrokers who flocked together to execute their orders at fixed prices (à cours fixe). Stockbrokers noted the price at which a transaction was effected on a slip of paper. These prices (cours faits) were quoted by a stock exchange employee and published in the official list. Hence, the official lists could contain multiple prices for these securities each day. Whether securities were traded en groupe depended solely on the state of the market. There was no fixed list of securities which were traded en groupe. 10 For filling orders in less actively traded securities, stockbrokers had to approach a so-called teneur du marché or market maker. This was an unofficial function taken up by a broker in name only who was often affiliated with industrial or financial groups and specialised in trading a limited number of securities on his own account. During exchange sessions, teneurs du marché collected all buy and sell orders from stockbrokers. At the end of a session, after they had received all orders, the teneurs du marché balanced the orders and fixed the single price (cours unique) at which the highest number of orders could be fulfilled. This price was then quoted by a stock exchange official and published in the official list (François , p. ; François-Marsal , pp. -; Lamal , p. , , pp. -; Tienrien , pp. -). It should be noted that, unlike jobbers on the London Stock Exchange, teneurs du marché could arbitrarily reduce orders or abstain from quoting a price. Hence the teneurs du marché wielded an extraordinary market power, which they could abuse for their own advantage. After availing themselves of the available information on the tendency of the market, these market makers were able to set the price that best suited their own interests. Naturally, this distortion of the market provoked a lot of criticism from contemporaries, including the Antwerp Exchange Commission. It was argued, for instance, that the quoted prices did not reflect the fair competition of supply and demand (Documents parlementaires no. , pp. - [ July ]; Tienrien , p. ; Lamal , pp. -; Brassine , p. ). The reform initiated by the royal decree of  January  therefore tried to remedy these abuses by reintroducing a more stringent regulation of Belgian exchanges. It made compensation of orders by banks impossible by again requiring 10 Orders au cours moyen for securities traded en groupe were settled at the arithmetic mean between the highest and lowest quoted price.

V
Our discussion of price discovery and quotation on Belgium's principal stock exchanges during subsequent periods of regulation (-) and deregulation (-) has revealed a trade-off between immediacy, liquidity and transparency. Stringent rules imposed by the government, pursuing a conservative and interventionist economic policy, kept the market small prior to : a limited number of stockbrokers who were strictly intermediaries could trade in a narrow list of securities that were approved by the government. The open outcry, at least in Brussels, ensured the ex-ante and ex-post transparency of price formation, but at the expense of immediacy. A stockbroker could only execute an order when this security was called. If he missed it, he had to wait for the next call auction. All prices at which transactions were effected, as well as bid and ask prices, were called out loud and published in the official price list. The government favoured the transparency offered by the open outcry because it benefitted investor protection, but local interest groups favouring the commodities trade over financial transactions in Antwerp successfully blocked it. While Brussels' official lists at the latest from  offer a true and complete overview of prices and quotes, Antwerp's were less complete. Multiple low-voice bids, offers or trades could be made at different prices during a session, but only the price or quote that won the majority vote was printed in the official list. After the deregulation of , the number of securities on the official list as well as the number of brokers increased strongly. This paradoxically reduced on the one hand the necessity of opaque, unofficial markets such as the Lloyd bruxellois, but, on the other hand, also increased the opacity of price formation on the official markets. Securities transactions could now legally be effected outside the exchange and without the intervention of stockbrokers. The prices of these trades were of course not printed in the official list, which remained a record of transactions inside the exchange. But prices and quotes made by stockbrokers inside the exchange too could remain unpublished because they did not exceed certain thresholds or because stockbrokers simply decided not to inform the stock exchange authorities. In  the Brussels Stock Exchange Commission contributed further to obscuring market-trends by no longer publishing bid and ask quotes in its official price list. The regulations and official price list of the Antwerp Stock Exchange seem to have offered better guarantees for transparency from the end of the nineteenth century in this respect. After the securities trade at the Antwerp Exchange had long been overshadowed by the commodities trade, a revival during the last quarter of the century led to the securities trade moving to a separate building and detailed regulations for price discovery and quotation. The introduction of a limit order book in  and the continued publication of bid and ask quotes offered order transparency; the obligation to report all cours faits to the Exchange Commission provided price S T O C K E X C H A N G E R E G U L AT I O N A N D O F F I C I A L P R I C E L I S T S  transparency. In Brussels, less scrupulous stockbrokers could use the less stringent regulations to their personal advantage. It should be noted, however, that this was frowned upon by a large group of stockbrokers who shortly after the reform of  already pleaded for firmer regulation that would drive the former out of the professionregulation that was finally instated with the reform of . We expect that the higher level of transparency in Antwerp during this period was a consequence of its specialisation in trading government debt. These 'investment securities' (valeurs de placement), as one contemporary observer argued, traded with much smaller margins and therefore presented fewer opportunities for manipulation of prices by self-serving stockbrokers than speculative investments such as mining and industrial shares in which the Brussels Stock Exchange specialised (de Reynrode , p. ). To provide liquidity in often small issues, market makers necessitated a degree of opacity. Excesses such as those reported for Brussels, where stockbrokers working as market makers would unilaterally set prices in their own interest or simply refuse to set prices, were unknown in Antwerp, although minor complaints about price manipulation in Antwerp were not unknown (Documents parlementaires no. , pp. - [ July ]).