Does anyone who trades either the euro or yen futures use an index as a tool for forecasting future currency rates? For example, watching the Nikkei futures or Dow Jones Stoxx futures vs the S&P? If so what type of things do you look for, and what sort of time frame? For example, watch for Nikkei to rally against the S&P's on a 1 to 3 weighting before buying the yen, stuff like that. Any advice would be greatly appreciated.