Educational only, not tax, legal, or financial advice. Rules vary by broker and situation — verify specifics with your broker or a professional.

The Cboe (Chicago Board Options Exchange) is the largest US options exchange and the home of SPX options and the VIX. It’s foundational infrastructure for the options market.

What it is and lists

The Cboe pioneered listed options trading and now operates major markets. It lists the flagship SPX (S&P 500 index) options and XSP (Mini-SPX), and it created and calculates the VIX volatility index (from SPX option prices). The explosion of 0DTE trading centers heavily on Cboe’s SPX daily expirations.

Why it matters to options traders

If you trade index options, you’re trading Cboe products; even SPY traders are shaped by Cboe’s SPX/VIX ecosystem (the VIX drives the volatility read, SPX flows shape dealer positioning). The Cboe also publishes data and research on options-market structure that informs the whole dealer-flow world.

The Cboe is where index options live — SPX, XSP, and the VIX all trace back to it. Even SPY traders operate inside the ecosystem it anchors.

What it means for a scalper

You trade SPY (an ETF, options cleared across venues), but the Cboe’s SPX and VIX are the reference points — SPX 0DTE flows and the VIX regime shape your tape. Knowing the Cboe demystifies where the index-options world’s plumbing sits. Related: the market makers and OCC that complete the system.