ROE versus ROI: What Is the Denominator Behind an Exchange’s Return Percentage?

A futures position shows +150%. Neither the price nor the account necessarily grew by 150%. Exchanges commonly display ROE, return relative to position margin. The denominator can make identical PnL appear very different. Knowing what is divided by what prevents a misleading interpretation.

The numerator is the same; the denominator differs

ROE and ROI here use the same PnL numerator. The difference is what that amount is divided by.

The large percentage in a position window is commonly ROE. Labels differ: Unrealized PnL (%), ROE%, or a setting choosing margin versus notional. Changing the display setting can change the percentage for the same position. Check the denominator before interpreting it.

One position, three percentages

Assume a $5,000 account, a 20x BTC long and a 3% price increase.

All three figures are valid, but ③ measures the effect on your overall account. ROE 60% means 60% relative to the $400 committed to this position; it says nothing about the other $4,600 sitting outside it.

A high ROE does not itself mean a better trade. Higher leverage reduces required margin and the denominator, increasing the displayed percentage while PnL remains unchanged at fixed notional.

Changing leverage changes the percentage, not fixed-notional PnL

With the same notional amount, changing leverage does not change the PnL from the same price move. Only the required margin changes.

This explains why switching to 50x has not multiplied actual returns tenfold. At fixed notional, leverage locks less margin; notional determines the PnL. Measure exposure through notional rather than the display percentage, or the basis for position sizing becomes confused.

Leverage still matters. Thinner margin can bring liquidation closer to entry. The 50x example can approach liquidation after only around a 2% adverse move. The actual distance depends substantially on the margin mode, so examine cross versus isolated margin and liquidation calculations.

Costs missing from the displayed percentage

Unrealized percentages commonly reflect only the difference between entry and current price. Actual settlement includes additional costs.

This appears to reduce ROE by only around three percentage points, but costs become more significant with smaller targets. The same $12.8 is around 5% of a 3% target's $240 PnL, yet 53% of a 0.3% target's $24. This is how a correct direction can still leave little or negative net return. Check your fee tier and notional in the fee calculator and assess whether the target covers costs.

Unrealized PnL can also affect margin and liquidation, not merely the display. See unrealized PnL and margin.

Loss percentages are asymmetric

Recovering −X% does not require merely +X%. After a loss, the remaining-capital denominator is smaller.

An ROE of −80% does not necessarily mean an 80% account loss. In the earlier 20x example it could mean −6.4% of the account. Conversely, if half the account was committed as margin, −80% ROE means −40% of the account, requiring about +67% to recover. The account impact of the same ROE depends on allocation. Manage account-level drawdown.

This asymmetry also affects compounding: one large loss lowers the entire subsequent curve. The danger in high-leverage trading comes from poor allocation exposing the account to this asymmetry, rather than the large displayed ROE itself.

Keep records on an account basis

Simply averaging ROE across trades distorts performance because different margin amounts receive equal weight. A small position's large percentage can offset a large position's small percentage on paper.

Record at least entry price, exit price, notional, margin, fees and net PnL. These six fields allow later recalculation of ROE, ROI and account returns; a percentage alone does not. Check individual trades with the PnL calculator and aggregate money amounts.

Recap

A percentage is incomplete information without its denominator. Before interpreting +150%, check what it divides by, its account-level equivalent and the amount remaining after costs.