A $40 billion institutional trade cycles through Vanguard’s S&P 500 exchange-traded fund (VOO) every quarter, affecting retirement account holdings, Bloomberg reported.
Foreign institutions are behind the quarterly movement, exploiting a scheduling gap between VOO and BlackRock’s iShares Core S&P 500 ETF (IVV) to sidestep U.S. dividend taxes.
The two funds track the same index and charge the same 0.03% annual fee, but they distribute dividends on different dates each quarter, Bloomberg confirmed.
That scheduling gap lets overseas investors sidestep the 30% United States withholding tax on dividend income from both funds.
The strategy probably saved foreign investors an estimated $147 million in U.S. taxes last year, and the next rotation is expected around Sept. 15, 2026, according to Bloomberg calculations.
The trade is legal, but the friction costs fall on domestic shareholders who hold VOO or IVV through each quarterly rotation cycle.
How staggered dividend dates on VOO and IVV enable a tax-free rotation
VOO and IVV hold the same 500 large-cap stocks, giving a dollar in one fund the same economic exposure as a dollar in the other, Bloomberg reported.
The key difference is timing: IVV’s third-quarter ex-dividend date falls on Sept. 15, 2026, and VOO’s arrives about two weeks later, near the end of the month, according to BlackRock’s 2026 distribution schedule.
Under the Internal Revenue Code, foreign investors owe a 30% withholding tax on U.S.-source dividend income, though tax treaties reduce the effective rate to 15% or lower for many institutional holders. The rotation avoids the levy entirely, regardless of treaty rate.
Foreign institutions exit IVV before its ex-dividend date, move the capital into VOO, then reverse course before VOO pays its own quarterly distribution.
Share prices typically fall by the dividend amount on the ex-dividend date, so selling beforehand converts the payout into untaxed capital gains.
That process provides overseas investors with continuous S&P 500 exposure, with no taxable dividend income and no withholding liability on distributions from either fund.
Museum Mile Funds CEO Mayank Mohan told Bloomberg that the strategy became viable only after multiple large, low-fee S&P 500 ETFs existed for institutions to rotate among.
<strong>With the emergence of IVV and VOO you have the availability of doing these switching trades</strong>.
The flow pattern first became visible in fund flows in 2023 and has grown in dollar volume since, Bloomberg’s investigation documented.
Treasury scrutinizes ETF tax strategies but excludes the direct rotation
At a Wall Street Tax Association seminar on July 21, 2026, senior Treasury officials raised public concerns about multiple categories of ETF-based tax strategies, noting that certain products under review may produce outcomes inconsistent with what Congress intended, according to Bloomberg.
“We’re not here to be over-broad or disruptive, but we are also not prepared to turn a blind eye to aggressive planning,” Kevin Salinger, acting assistant secretary for tax policy at the U.S. Department of the Treasury, said at the seminar.
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The strategies under review included funds that avoid dividend income by rotating among other ETFs, fitting the mechanism behind the IVV-VOO quarterly trade.
When Sullivan & Cromwell partner Jeffrey Hochberg asked whether concerns extended to foreign investors executing the direct rotation, U.S. Department of Treasury Senior Counsel Erika Nijenhuis replied, “That’s not a focus,” according to Bloomberg.
Treasury’s scrutiny targets packaged investment products that bundle switching mechanics inside fund wrappers.
The department stopped short of announcing new rules, with officials saying they “expect a serious dialogue with the market before positions harden,” Bloomberg reported.
Michael M. Santiago / Getty Images
Why the rotation’s tax benefit skips domestic VOO and IVV holders
The costs imposed on everyday investors by the quarterly rotation are real, though they remain modest on a per-share basis for most long-term holders, Bloomberg confirmed.
When tens of billions of dollars shift between two nearly identical funds at once, bid-ask spreads can temporarily widen, and short-term tracking error can appear.
The structural asymmetry is that the tax benefit flows entirely to foreign institutions.
An American investor in either fund receives the quarterly dividend, pays applicable tax, and bears a share of the rotation’s frictional costs, with no comparable advantage from the trade.
The forgone tax revenue has reached a meaningful scale, and the savings flow mainly to wealthy participants, Robert Morris University professor Steven Hodaszy noted, according to Bloomberg.
What the September rotation means for VOO and IVV holders
Vanguard’s VOO and BlackRock’s IVV have continued to deliver low-cost S&P 500 exposure at a 0.03% fee, with the quarterly rotation cycling through their share bases without altering that structure, according to both fund providers’ 2026 disclosures.
For U.S. holders, the trade-off is small on a per-share basis. It shows up as slightly wider bid-ask spreads and brief tracking error around ex-dividend dates.
IVV’s next ex-dividend date lands on Sept. 15, 2026, with VOO’s following in late September. Any real change to the pattern would need formal Treasury guidance aimed at the switching mechanism itself, and the department has not signaled that step.
Related: Vanguard’s VOO faces something it never has before
