none of the above. just a plain old sale of stock. you paid nothing, and I assume nothing was included on your W-2 for it 's " value" so that's your cost basis. The company paid you X to buy it back, that's your sale price. the date they gave it to you was the date acquired and the date the bought it is the date sold.
However, do check with your employer as to whether anything was included on your w-2 in the year they gave it to you.
that would change my answer.
