Glossary/Binary option
Binary option
A binary (digital) option pays a fixed payoff if a condition is true at expiry and nothing (or a smaller fixed amount) otherwise. Prediction-market Yes/No and crypto Up/Down contracts are economically similar to short-dated binaries settled on an observable.
How AymarData records it
Polymarket Up/Down families (for example btc-updown-15m) and many Kalshi event contracts behave like binaries. AymarData stores their L2 books, trades, and settlements so you can backtest entries against resolution. Start at /data/polymarket and the backtest guide.