That’s not what tax loss harvesting is. Say you own VTI, a total US market etf. Then the stock market drops 20% next week. You can sell VTI and with the proce

That’s not what tax loss harvesting is. Say you own VTI, a total US market etf. Then the stock market drops 20% next week. You can sell VTI and with the proceeds immediately buy VOO (s&p500 etf) within seconds. VOO and VTI are insanely correlated, so you’ve basically triggered a 20% loss for tax purposes, without actually selling any of your exposure. That said, it’s not as big of a value as you might think, since you’ve also stepped down your basis, and need to pay more capital gains taxes when you sell since you “bought” at a lower price now. Generally accepted wisdom is to TLH up to the yearly loss deduction amount (like 3k or so) and stop.