Breakeven calculator
Gap Scout returns the odds price ever touches either level before the horizon — not merely where it finishes.
I also know my T+0 lines — the line that actually moves today
Session 1 language: the expiration break-evens are the tent you own at the end; the T+0 line is what price is actually pressing against today. Enter both and Gap Scout reads them side by side.
Your five plays
A reference card, not a recommendation. These are the five adjustments from the course — Gap Scout gives you the odds and the side under pressure, and you decide which play the situation calls for.
- A.01 · Slippity Slide
- A.02 · Catcher’s Mitt
- A.03 · Squeeze Play
- A.04 · Double-Wide
- A.05 · Wing Rip
How it works
It prices the implied move from the index’s own option-market volatility, tilts it for put skew (downside tails are fatter than upside) and for the directional lean in the current read, then measures where your two levels fall on that distribution. The horizon sets the vol: rest of day prices off the 1-day implied vol and shrinks on its own as the session runs down; overnight, this week and expiration use the 30-day implied vol, stretched by the square root of the time remaining.
Touch odds are the headline. “Never touches either” asks whether price stays inside your tent the whole way — not merely where it finishes. That matters because a level that gets tagged intraday has already forced your decision, even if price closes back inside. Closing odds flatter a range; touch odds tell you what you will actually live through.
The current-vol box is a what-if. It takes an actual reading, not a point change. It pre-fills with the value captured at the last refresh — type what your platform shows now and every number re-scales. The vol-index spot (VIX and friends) runs a few points above the index’s own at-the-money implied vol, because it prices a wider strip of out-of-the-money options; that is why the two never match exactly, and the strip above always labels which one is sizing the bands.
⚠ These are estimates, and they age. Volatility, skew and the directional lean come from the last refresh; only your inputs and the clock keep updating between refreshes. Options-implied probabilities describe what the market is pricing — they are not a forecast, real-world tails are fatter than any normal curve, and nothing here accounts for your position size, spreads or fills.
The math runs entirely in your browser. Your price levels are never sent anywhere — the only things this page fetches are its own inputs file and its fonts.