非退休账号下,不仅可选first,last，还可以选任何日买进的卖,可以根据你自己保税情况决定。tax loss har

Tax-loss harvesting is a way to cut your tax bill by selling investments at a loss in order to deduct those losses on your taxes. Deducting those losses can offset some or all of the capital gains tax you might owe on other investments that you sold for a profit