1. One who buys and sells securities for his/her personal account, not on behalf of clients. 2. An investor who holds stocks and securities for a short period of time (a few minutes, hours or days). The goal is to profit from short-term gains in the market. The stock selection is generally based on technical analysis or charting which relate only to the stock price rather than a fundamental evaluation of the company as a business. The IRS offers some tax benefits to traders: they can deduct their interest expense without itemizing, and seminar costs can be deducted as well as home office expenses in connection with investing.