Option sellers receive premium upfront in exchange for taking on assignment risk.
### Early Assignment American-style options can be exercised by the buyer at any time before expiration. Early assignment happens most frequently when: 1. Short Call is ITM right before an ex-dividend date. 2. Short Put is deep ITM with very little remaining time value (extrinsic value).
### European-Style Options European-style options (such as SPX or Nifty index options) can only be settled on the exact expiration date, eliminating early assignment risk.
You are obligated to sell 100 shares of the underlying stock at the short call strike price. If you own the stock (Covered Call), your shares are called away.