In trading, an activity that exactly cancels the risks and benefits of another instrument in the portfolio. An offsetting transaction is used when it is not possible to simply close the original transaction as desired. This frequently occurs with options and other more complex financial instruments.
In this way, a trader does not have to agree to close the option contract with the party on the other side of the options trade, but can simply cancel the net affect by entering into an offsetting transaction.
The most basic example of an offsetting transaction occurs in options trading. Suppose you have sold a call option on 100 shares with a strike price of $35 and an expiration in three months. To close this transaction before three months is over, you can buy a call option with exactly the same features, thus exactly offsetting the exposure to the original call option.
Offsetting transactions typically do not factor in transactions costs.