Why does a 2× fund not deliver 2× over a year?
A leveraged fund promises twice its index's return. It keeps the promise every day, and that is exactly why it breaks it over a year. This is arithmetic, not marketing, and it is worth doing by hand once.
The daily reset
A 2× fund holds derivatives sized so that today's move is double the index's move. Tonight it resets the exposure to twice tomorrow's starting value. Every day starts fresh at 2×. The consequence is that the fund compounds the doubled daily moves, and compounding doubled moves is not the same as doubling the compounded move.
Two days by hand
The index rises 10% on Monday and falls 10% on Tuesday.
- Index: 100 → 110 → 99. Down 1% over the two days.
- 2× fund: 100 → 120 → 96. Down 4%.
- −1× (inverse) fund: 100 → 90 → 99. Down 1%, on an index that also finished down 1%.
Nobody lied. Each day the funds did exactly what they said. Over two days the leveraged fund lost four times what the index lost, and the inverse fund lost money on an index that fell. The mechanism is the percentage-asymmetry lesson from foundations — a loss needs a bigger gain to undo it — applied twice as hard.
Volatility is the fee
Over many days, the gap between a leveraged fund and its multiple grows with how much the index bounces. A useful approximation from the arithmetic of compounding: the extra annual drag on a 2× fund is close to the index's variance — its annual volatility squared. At 18% volatility, the number the risk course gave for a broad index, that is about 0.18², a little over 3% a year, before the fund's fee. At 40% volatility it is about 16% a year. In a sideways, choppy market a 2× fund can lose money while its index goes nowhere, and a −1× fund can lose money while the index falls.
Trending markets do the opposite: a steady rise compounds in the fund's favour and it can beat 2×. The fund is not broken either way. It is a bet on the path, and the label describes only the daily step.
Who they are for
Traders holding for a day, for whom the promise is exactly right. Anyone holding for a quarter is holding a product whose behaviour depends on the volatility of the path, which nobody can forecast — and the funds' own documents say, in plain words, that they are not intended to be held long-term. The problem is not the product; it is the assumption that a long-run 2× exists to be bought.
How to check one
Two things on any leveraged or inverse fund, before anything else. Its multiple and its reset period — daily for almost all. And its expense ratio, which runs from about 0.9% to well over 1% a year, on top of the path drag. Then the test from the risk-and-return course: what has it done over a year against twice its index, measured, not assumed.
In the data
A fund's classification rarely flags leverage; its name does. 2x, Ultra, Daily, Inverse and Short are the tells. Then the test: a 2× fund on the S&P 500 beside the plain S&P 500 fund, both as their providers report them:
Double the plain fund's one-year return and set it beside the leveraged fund's. The shortfall is the path drag plus the higher fee, and the volatility lines show where it came from: the 2× fund bounced twice as hard, and the drag grows with the square of the bounce.
Try it now
- Do the two-day sum above for a 3× fund and a −2× fund, by hand. Then extend to four days: up 10%, down 10%, up 10%, down 10%. Watch the gap open.
- Take a real year of a broad index and count how many days it moved more than 1% either way; the ratio of one close to the previous is the daily move. Measured on 28 September 2026 from the S&P 500 fund's daily closes, the year from 2 September 2025 to 25 September 2026 held 268 daily moves, 51 of them larger than 1% either way. The year is below as daily bars: Measure close to close across any one month, count its 1% days yourself, and scale your count to a year to see whether it lands near 51. The count is a rough gauge of the volatility a 2× fund would have paid for that year.
- The annualised volatility of those same 268 daily returns, computed the same day, was 12.68%. Square it, and write the number down as "the annual price of holding 2× on this, before fees". Then add the expense ratio of the leveraged fund below, ProShares Ultra S&P500, a 2× fund on the same index. That sum is the hurdle the fund has to clear before it delivers any of its promise over a year.