The placement of a buy or a sell order (or opening of a buy or a sell position) and closing it on the same day before the market closes for business. It is the trading activity carried out by a market participant during the market hours in one day (i.e., within the day.)

Day trading is mainly about speculating on the prices of securities based on market analysis using quantitative, technical or fundamental indicators. Hence, it is a very risky type of trading, but potentially can produce abnormal profits. An example is when a trader buys 100 stocks of XYZ company during the opening of the market, then tries to sell the 100 XYZ stocks before the market closes for that trading day, capitalizing on the difference between purchase price and selling price during the same trading session.

Day trading is also known as a intraday trading.