Call Overwriting, also known as covered call writing or sell writing, is a options trading strategy in which an investor writes (sells) call options on a security that he or she already owns. By selling the call options, the investor collects the premium paid by the buyer of the options. The investor retains the right to continue holding the underlying security and potentially receive any future appreciation in its price.

The call overwriting strategy can be used as a way to generate additional income from an existing investment, or as a way to reduce the cost basis of the investment by offsetting some of the purchase price with the premium received from selling the call options. However, the potential for profit is limited to the premium received, plus any appreciation in the underlying security's price up to the strike price of the call options. If the underlying security's price rises above the strike price before the options expire, the investor may be required to sell the security at the strike price, forgoing any potential further appreciation.

Call overwriting is a moderately risky strategy because the investor is exposed to the potential for capital appreciation in the underlying security, as well as the risk of being required to sell the security at the strike price if the options are exercised. It is important for investors to carefully consider the potential risks and rewards of this strategy before implementing it.