We use existing currency models, global capital flows, international parity, the Taylor rule, and some simplifying assumptions to derive and empirically test a link between the information contained in currency option-implied volatilities and future global equity correlations. Using data from January 1999 to May 2020, we test our hypothesis and find that exchange rate option-implied volatilities - coupled with one-period ex-post correlations - more accurately predict subsequent world equity market correlations than other models. Our findings have implications for portfolio diversification, forecasts of overall equity portfolio volatility, and portfolio optimization.