Capitalizing on the special case of Malaysia in which proprietary day traders (PDTs) are mandated to boost liquidity and the recent availability of trading data, this paper empirically examines the liquidity effect of proprietary day trading. Using daily data spanning October 2012 to June 2018, we find evidence that PDTs’ trade volume is associated with higher aggregate liquidity in the Malaysian stock market, which can be attributed to the theoretical channel of intense competition among informed traders. However, such improved liquidity comes at a cost to investors, as proprietary day trading is found to be associated with higher conditional volatility and conditional skewness of closing percent quoted spreads. The former is due to the exchange-imposed immediacy for PDTs to close their open positions, whereas the latter can be attributed to the exclusive rights granted to PDTs to engage in intraday short selling.
Day traders; Liquidity; Liquidity volatility; Liquidity skewness; Malaysia