Back in 2014 I exercised employee stock options at a price of $18.73. The FMV at the time was $56.41 and I had to pay AMT based on the FMV even though I did not sell my shares that year. I sold some shares in 2019 which used up the majority of the AMT credit carryforward. This year I sold the remainder of the shares. Is the cost basis the FMV price of $56.41 or the exercise price of $18.73 since my AMT credit carryforward is zero now or is that not a factor? Thanks!
