The Trade That Looks Like a Mistake
Imagine selling a stock for less than you paid, on purpose, in the same breath that you’re buying something almost identical. To anyone glancing over your shoulder, it looks like panic selling. In reality, it’s one of the few moves in investing where losing money on paper actually works in your favor at tax time. The strategy is called tax-loss harvesting, and it’s quietly used by financial advisors every December to shave real dollars off their clients’ tax bills.
How the Offset Actually Works
When you sell an investment at a loss in a taxable brokerage account, that loss isn’t just a disappointment, it’s a deduction. The IRS lets you use realized losses to cancel out realized capital gains dollar for dollar. Sold a stock for a $4,000 profit this year? A $4,000 loss elsewhere wipes that gain out entirely, and you owe nothing on it. If your losses exceed your gains, you can still use up to $3,000 of the excess to offset ordinary income on your tax return, and whatever is left over carries forward into next year, indefinitely, until you use it all.
The Wash-Sale Rule You Cannot Ignore
Here’s where most beginners trip up. The IRS does not let you sell an investment for a loss and then buy back the exact same security within 30 days before or after the sale. Do that, and the loss is disallowed under what’s called the wash-sale rule. The workaround that professionals use is buying a similar, but not identical, fund in the meantime. Sell an S&P 500 index fund at a loss, then temporarily hold a total-market index fund instead. You stay invested in roughly the same market exposure while the 30-day window passes, then you can switch back if you want to.
Why December Isn’t the Only Time to Do This
Most people only think about harvesting losses in the final weeks of the year, scrambling before the tax deadline. But markets dip throughout the year, and every dip is a potential harvesting opportunity. Some robo-advisors now run this process automatically, scanning your portfolio daily for small losses worth capturing. Doing it continuously, rather than once a year, generally captures more total losses than waiting for a year-end review.
Who Should Actually Bother
This strategy only applies to taxable brokerage accounts, never to 401(k)s or IRAs, since those already grow tax-deferred or tax-free. It also matters most if you’re in a higher tax bracket or you’ve had a year with sizable capital gains from selling a stock, a business, or even cryptocurrency. If most of your investing happens inside retirement accounts, tax-loss harvesting won’t do much for you, and that’s fine. But for anyone with meaningful money sitting in a regular brokerage account, it’s a strategy worth understanding before the next market dip arrives, because the losses you don’t harvest are tax savings you’re leaving on the table.
