The strategy, designed to track stock indices while generating losses to offset capital gains taxes, has surged from $2 billion in 2022 to its current level. However, tax lawyers and investment experts warn that many investors do not fully understand its complex details and investment implications, and the rapid growth of these assets has attracted scrutiny from tax authorities. U.S. Treasury officials have previously warned against "aggressive planning" and stated they would not allow "complex abusive tax structures to become a runaway train," hinting at potential new guidance or prohibitions. Experts point out that the TALS strategy is essentially more akin to tax deferral than permanent savings, and investors may face a large lump-sum tax bill upon exit.