An arbitrage operation in which an investor takes a long position in one type of security and a short position in a similar security in an attempt to profit from a change in the basis between the two securities. For example, an investor might purchase a call with an April expiration and simultaneously sell short a call with a different expiration or strike price on the same stock. The investor expects that the values of the two positions will change over time such that a profit will ensue. Basis trading is undertaken when the investor feels one security is priced too high or too low relative to the price of another security. Because of this, the profit on one side of the trade should more than cancel out the loss on the opposite side of the trade. Basis trading may involve an index or group of securities as well as individual securities. Compare program trading. Also called relationship trading.
