The carry of an asset is the return obtained from holding it (if positive), or the cost of holding it (if negative) (see also Cost of carry). For instance, commodities are usually negative carry assets, as they incur storage costs or may suffer from depreciation. (Imagine corn or wheat sitting in a silo somewhere, not being sold or eaten.) But in some circumstances, appropriately hedged commodities can be positive carry assets if the forward/futures market is willing to pay sufficient premium for future delivery. This can also refer to a trade with more than one leg, where you earn the spread between borrowing a low carry asset and lending a high carry one; such as gold during financial crisis, due to its safe haven quality.

Carry trades are not usually arbitrages: pure arbitrages make money no matter what; carry trades make money only if nothing changes against the carry's favor.