How Do Gas Fees on a Decentralized Exchange Impact the Calculation of Capital Gains/losses?

Gas fees (transaction costs) paid on a decentralized exchange are generally treated as an addition to the cost basis of the acquired asset or a reduction of the amount realized on a sale. For a derivative trade, the gas fee can be added to the cost of opening the position or subtracted from the proceeds of closing it, directly impacting the capital gain or loss calculation.