Married Put

Buying stock and buying a put on the same shares at the same time is the married put, and this workbook prices both sides together. The put sets a floor at its strike for the life of the contract while the shares keep their full upside, with the premium paid as the cost of that floor.

Share price comes from the last price formula, and the put's bid, ask and previous close arrive on demand once the option symbol is built from your strike and expiration, so the net cost basis and the protected floor recalculate as the market moves.