Help24
Returning Member

1099-B with no cost or other basis

I received a 1099-B with no cost basis as a result of a non-qualified stock option sale (cashless) in 2023.  The only thing listed on the 1099 is proceeds.  All other boxes are blank except for one this checked for non-covered security.  I checked my W2 and nothing listed in Box 12.  How do I calculate my cost basis?