Futures pointed to a 0.2% gain for the S&P 500, which closed Monday at its best level since November. Changes in futures markets don't necessarily reflect market moves after the opening bell.
The yuan posted its biggest two-day drop versus peers since February, spurring speculation the authorities are weakening the currency to counter a slowing economy.
Gold eased on Tuesday as investors turned cautious after the metal failed to sustain a recent rally, though it held near the previous day's two-week high after the Federal Reserve further dampened speculation about an imminent U.S. rate rise.
- USDJPY: 107.57
- EURUSD: 1.1355
- S&P 500: 2,109.41
- NASDAQ : 4,968.71