0DTE — same-day-expiry — options are not different in mechanics from any other option contract. They expire by the closing bell of the trading session in which they were opened. The only thing that changes is the speed at which their value moves and the discipline required to manage them.

This cluster covers the foundations: what a call is, what a put is, why expiration matters, and why defined-risk structures are the only way most retail traders should approach 0DTE.

If you are new to options entirely, start here. If you already know the basics from longer-dated trades, this cluster will reframe them through the 0DTE lens.