single rate; single exchange rate
Financial term for a single, unified exchange rate, as opposed to multiple or tiered rates. Used in contexts like foreign exchange or trade.
This bank adopts a single exchange rate.
Compound of 一本 (one, single) + 建て (立て, here meaning 'setting' or 'establishing') + 為替 (exchange, money order). The exact historical derivation is uncertain; the term is a technical financial expression.