Day trading is most common;y observed in the stock markets and on the foreign exchange (forex) where currencies are traded.
Day traders are attuned to events that cause short-term market moves. Trading based on the news is one popular technique. Scheduled announcements such as the release of economic statistics, corporate earnings, or interest rate announcements are subject to market expectations and market psychology. That is, markets react when those expectations are not met or are exceeded—usually with sudden, significant moves which can greatly benefit day traders.