Tax loss harvesting (TLH) is an investment strategy for "generating" capital losses to gain a tax advantage. It occurs when an investor sells a security that has depreciated in value only for the tax losses.[1][2] The effectiveness of this approach is dependant of the tax rules in a particular jurisdiction. In the United States CBS News describes tax loss harvesting specifically as "selling an investment at a loss with the intention of ultimately repurchasing the same investment after the IRS's 30 day window on wash sales has expired." This allows investors to lower their tax amount with the use of investment losses.[3]
Tax loss harvesting can be done throughout the fiscal year but historically has been performed in December.[4] Tax-loss harvesting is still most common in the year's fourth quarter. This allows investors to "offset capital gains with capital losses."[5] Under United States tax rules, if an investor has more capital losses than gains in a year, that year they can use up to $3,000 as a deduction to "offset ordinary income", with the remainder carrying over into future years if unused.[6]
Loss harvesting defers taxes, but doesn't eliminate them, and is essentially receiving a loan without interest from the federal government, assuming marginal tax rates are the same.[7] If marginal rates are different, then there can be additional tax savings (e.g., deducting excess losses against a higher ordinary income rate in one year in exchange for additional long term capital gains tax at a lower rate in a later year) or even a tax penalty (e.g., deducting at a lower capital gains tax rate in several years in exchange for a much larger gain in one later year that puts one in a higher capital gains tax and Medicare investment income tax bracket.)[8]
The practice of tax loss harvesting has been both praised and criticized by investors, as deferring the taxes can result in higher rates later on relating to capital gains.[8]