Commodity futures structure refers to the mechanics of forward curves (contango, backwardation, roll yield), physical delivery constraints, and how fundamental supply/demand dynamics are encoded in the term structure — distinct from financial futures markets.
Commodity trend strategy performance is routinely evaluated on price returns, with roll yield treated as a minor implementation detail. In markets with persistent contango (natural gas, crude in some periods), roll yield drag can be 3-7% per year — enough to turn a trend strategy with +0.4 Sharpe on spot prices into a net negative. The return decomposition into spot P&L and roll P&L is not optional accounting; it determines whether the strategy has any edge at all in specific sectors.
Financial futures converge to a settlement price that cannot deviate from fundamental value by more than transaction costs. Commodity futures have physical delivery mechanisms that can create theoretically unlimited short-term dislocations when storage is exhausted — as WTI crude proved in April 2020 by trading to -$37. No position sizing model accounts for the fact that a "small" crude position held into expiration could have effectively unlimited loss if physical storage disappears. This tail risk is categorically different from the normal vol-scaled risk that governs sizing.