Resumen
The main objective of this study is to analyze the empirical effects of the introduction of market makers in the Brazilian stock exchange. By aggregating information regarding the dates of the market maker?s contract and the use of a privileged high frequency database, it was possible to execute an event study to check the effect of the introduction of liquidity agents. As expected, the period after the beginning of the market maker?s contract presented a significant increase in the liquidity of the stocks. The study reports an average increase of 31% in the number of trades in the period before and after the start of the contract. Another result is that the work of a liquidity agent can change significantly the autocorrelation of the trade signs in approximately 10%. Such a result is stronger for the stocks with lower liquidity. The investigation also shows heterogeneous results for the performance of the liquidity provision when the analysis based itself on the financial institution of the market maker. Such information is particularly important for companies that are seeking to contract market making services.