The Futures Payoff
Straight-line profit and loss in both directions — and why that symmetry cuts both ways.
A “payoff diagram” plots your profit or loss against the underlying’s price. For futures it’s the simplest diagram in all of derivativesA contract whose value is derived from an underlying asset.: a straight diagonal line. Every point the underlying moves translates one-for-one into your P&LA record of revenue, costs and profit over a period..
- Long futureA binding agreement to buy or sell at a set price on a future date. — a line sloping up: profit grows as price rises, loss grows as price falls, point-for-point.
- Short futureA binding agreement to buy or sell at a set price on a future date. — a line sloping down: profit as price falls, loss as price rises.
- No asymmetry — unlike optionsThe right, not the obligation, to buy or sell at a set price., there’s no limited-loss side; gains and losses are mirror images around your entry.
Why is a short future’s loss called “unlimited”?
Because a stock’s price can rise indefinitely, a short future (which loses as price rises) has no theoretical ceiling on its loss. A long future’s loss is bounded only by the price falling to zero. In practice, daily mark-to-market and stops cap real losses — but the *theoretical* downside symmetry is why futures demand strict risk control.