Volatility decay describes how fluctuations can erode compounded returns, particularly in leveraged products that reset their exposure. Each percentage return applies to a changing capital base, so an asset's final price alone does not determine a leveraged product's result.
A round trip with different outcomes
Assume an underlying asset starts at 100, rises 10% to 110, then falls back to 100. The second day's decline is approximately 9.09%, not 10%.
Now assume a hypothetical product delivers exactly twice each day's underlying return and resets to 2× leverage daily, with no fees, funding costs or tracking differences. Starting at 100, it rises 20% to 120, then loses approximately 18.18%, finishing near 98.18. The underlying is unchanged over both days, while the product loses about 1.82%.
A path effect, not a fixed charge
The loss in this example comes from compounding the two leveraged returns. It is not a separate fee deducted by an exchange. Real products may also incur management, trading and funding costs.
Volatility decay does not mean every leveraged product must fall every day or over every holding period. Persistent trends can produce favorable compounding. Results depend on the return path, leverage and reset rules; products with conditional or different reset schedules need their own analysis. Simply multiplying the underlying's total return by the advertised leverage can therefore be misleading.