We study two parties who desire a smooth trading relationship under condi- tions of value and cost uncertainty. A contract ﬁxing price works well in normal times because there is nothing to argue about. However, when value or cost is unusually high or low, one party will deviate from the contract and hold up the other party, causing deadweight losses as parties withhold cooperation. We show that allocating asset ownership and indexing contracts can reduce the incentives to engage in hold-up. In contrast to much of the literature, the driving force in our model is payoff uncertainty, rather than noncontractible investments.