Hey Tigers，Hello everyone — Selina here. Thank you for Tiger brokers having me for this live. A lot of you have asked me about $S&P 500(.SPX)$ 0DTE options. How they work. Why they've exploded. Whether they're "dangerous" or just "different." The short answer: they're the most significant structural change in options markets since the introduction of weeklys. And if you're trading equities — even if you never touch an option contract — you need to understand how 0DTE flow affects the stocks you own. Here's the thing: I've spent over a decade inside this market. At Cboe, I built the analytics, wrote the research, and sat in the rooms where regulators asked "what's actually happening here?" Now I run Han Insights, and my job is to translate that