The movement of the price of a
futures contract toward the price of the
underlying cash commodity. At the start, the
contract price is usually higher because of
time value. But as the contract nears
expiration, and time value decreases, the
futures price and the
cash price converge. More generally, convergence trading involves taking two related assets that have different prices with the expectation that prices will converge (the cheaper asset is purchased and the more expensive is sold short).