SPXW 0DTE: What Every Developer Building Options Tools Needs to Know

If you've built anything involving options data, you've probably noticed that "SPX 0DTE" is everywhere on fintwit, Discord, and trading blogs. The thing most guides gloss over is that plain SPX doesn't actually have same-day expirations every day . What everyone means when they say "SPX 0DTE" is SPXW — a different ticker with different settlement and different Greeks behavior. I build an options analytics API, and the distinction matters enough that every developer touching options data should u