This note draws an analogy between deviations from no-arbitrage forward-spot relationships in currency and in commodity markets. The key is to notice that the U.S. dollar acts as a commodity in foreign exchange (FX) markets. In the physical commodity space, if the spot price is too high relative to the futures price, then arbitrageurs will seek to short the commodity (priced in U.S. dollars) and invest the proceeds in a dollar-denominated bank deposit. A scarcity of the commodity entails a limited ability to borrow it, resulting in a positive "convenience yield." In the FX space, it is the dollar itself that needs to be borrowed - with the proceeds converted spot and invested in a foreign currency-denominated bank deposit. A dollar scarcity in the global lending market brings about widespread covered interest parity (CIP) deviations characterized by negative "cross-currency basis" for multiple U.S. dollar/foreign currency pairs. In both spaces, a scarcity or shortage of the underlying commodity generates the pattern. In other words, a (negative) "cross-currency basis" is the U.S. dollar's (positive) convenience yield.