Tax-Loss Harvesting: Turning Down Years Into a Tax Advantage

Tax-loss harvesting is the practice of deliberately selling an investment that has fallen in value in order to realise a loss, which can then be used to offset taxable gains elsewhere in your portfolio — or, within limits, against ordinary income. It's one of the few tax strategies where a bad year in the market can still work in your favour.

The mechanics are straightforward: if you sell one holding at a loss and another at a gain within the same tax year, the loss reduces the taxable amount of the gain. In many jurisdictions, if losses exceed gains, a limited amount can be deducted against ordinary income, with any remainder carried forward to future years.

The main trap is the wash-sale rule, which disallows the tax loss if you buy the same or a 'substantially identical' security within a window around the sale — typically 30 days before or after. Investors who sell a stock at a loss and immediately rebuy it to maintain their position can find the loss disallowed entirely.

A common workaround is to sell the losing position and buy something similar but not identical — for example, swapping one broad market index fund for a comparable one from a different provider — to maintain market exposure while the wash-sale window passes.

Harvesting is most effective as a continuous habit rather than a single December scramble: checking for opportunities through the year means you're less likely to sell into an already-recovering position purely to hit a year-end deadline.