in-and-out

Involving the purchase and sale of a single security within a short period of time.

The purchase and sale of a security within a short period of time, usually on the same day.

Investopedia Says:
Generally speaking, this is the strategy of day traders, where they attempt to profit by buying or short selling large quantities of stock to capitalize on small changes in price.

Related Links:
Curious about what it means to 'outperform the market'? Learn about an investing style that aims to do just that. Defining Active Trading
Learn about this controversial way of investing. Day Trading: An Introduction