When you strip the noise away, the real question is simple: tax-loss harvesting is a timing tool, not a wealth tool. Mechanism: When you sell a losing position to offset gains, you are deferring taxes, not eliminating them. The deferred tax becomes a zero-interest loan from the government. Why it matters: That matters because investors sometimes treat harvesting as free return when it is really a cash-flow advantage that benefits long holding periods. $$ Tax\ Deferral\ Value \approx Tax\ Saved \times r \times T $$ Plain English: The value of deferral is roughly the tax saved times the return you earn on that capital for the remaining holding period. Market translation: Selling a $10k loss to offset $10k of short-term gains at a 35% bracket defers $3,500 in taxes. The value depends on what you do with that capital between now and eventual realization. Failure mode: The mistake is harvesting indiscriminately without checking wash-sale rules or whether the replacement position changes the portfolio's intended risk profile. Review question: Before sizing up, identify whether the edge comes from cash flow, volatility, timing or balance-sheet structure. The point is not to memorize the label. The point is to know what variable is actually doing the work.