The international role of the U.S. dollar is often summarized through whichever indicator is moving most visibly: the exchange rate, the dollar share of official reserves, central-bank gold purchases, Treasury demand, SWIFT payment shares, stablecoin issuance, or the growth of alternative settlement systems. Each of these indicators contains information, but none of them can carry the whole argument because the dollar is a bundle of functions rather than a single object. It is a reserve asset, a vehicle currency, an invoicing unit, a funding currency, a collateral asset, a safe-haven instrument, and a settlement unit. […]