In reference to structured products, an accumulator contract is where the buyer speculates a company will trade between a certain price range (the range between the strike and the knock-out) within the contract period and the issuer bets that stock will fall below the strike price. The buyer holds an obligation to buy the shares at the strike price not the option to buy, whereas the issuer holds an obligation to sell shares at the strike price. Allows you to accumulate stock positions over time. (see also decumulator or structured products)