A programming error resulted in the issuance of a forward contract that ignored the convenience yield investors realize from holding the underlying asset. To gain an arbitrage profit from this error, an arbitrageur’s position would most likely include a long position in the:

Ignoring the convenience yield (a nonmonetary benefit of holding the asset) will result in a forward price that is above the no-arbitrage forward price. To profit from this mispricing, an arbitrageur would borrow at the risk-free rate (i.e., take a short position in the risk-free asset), purchase the underlying asset, and take a short position in the forward contract.