Tax loss harvesting is a popular tax planning strategy, especially as the end of the year approaches and investors consider their potential capital gains exposure. Yet for many investors, the benefit of tax loss harvesting is overestimated, as harvesting a loss generates current tax savings, but also reduces the cost basis of the investment, triggering a potential gain in the future that may offset most or all of the loss harvesting benefit!
Nonetheless, even if a harvested loss creates a future gain, there is still an opportunity for tax deferral in the meantime, which can create a modest but non-trivial economic benefit for tax loss harvesting. The benefits are further amplified – sometimes greatly so – if there is a potential that gains in the future will be taxed at a lower rate than losses harvested today, with the caveat that if brackets go the other direction, tax loss harvesting not only loses its positive value but can actually be wealth destructive!
To the extent that tax brackets changes are anticipated favorable, though – or at least, that rates will hold steady – some benefit to tax loss harvesting remains, and can be maximized with portfolios that hold a wide range of diversified positions (creating more loss harvesting opportunities), have ongoing contributions (again creating more loss harvesting opportunities), and are checked frequently for losses to harvest (as only trying to harvest losses in December can miss out on even greater intra-year loss harvesting opportunities!). And for those who are not at risk for adverse tax bracket changes, the tax loss harvesting opportunity is especially appealing in today’s environment, with transaction costs (including trading fees and bid/ask spreads) as low as they've ever been, and more opportunities than ever to own investment alternatives that minimize tracking error while navigating the wash sale rules!