Long Straddle Option Strategy

Buying a call and a put at the same strike and expiration gives a position that gains when the underlying moves far enough in either direction, and this sheet prices both legs along with the two breakevens. The most that can be lost is the total premium paid, which is also what the trade forfeits if the underlying sits still through expiration.

Bid, ask and previous close for each contract arrive on demand from the option symbol, next to the stock's last price, so the debit and the size of the move required recalculate as quotes change.