2008 Société Générale trading loss taken massive fraudulent directional positions in 2007 and 2008 far beyond his limited authority" and that the trades involved European stock index futures. Though bank officials say Kerviel apparently worked alone, skeptics question how unauthorized trading of this magnitude could go unnoticed. Kerviel's unassuming background and position have heightened the skepticism that he worked alone. Some analysts suggest that unauthorized trading of this scale may have gone unnoticed initially due to the high volume in low-risk trades normally conducted by his department. The bank said that whenever the fake trades were questioned, Kerviel would describe it as a mistake then
Pattern day trader For example, a trader may use 3 day trades, and then enter a fourth position to hold overnight. If unexpected news causes the security to rapidly decrease in price, the trader is presented with two choices. One choice would be to continue to hold the stock overnight, and risk a large loss of capital. The other choice would be to close the position, protecting his capital, and (perhaps inappropriately) fall under the day-trading rule, as this would now be a 4th day trade within the period. Of course, if the trader is aware of this well-known rule, he should not