As a general rule stock price indexes will inversely track the value of the currency they are denominated in relative to a basket of its trading partners currencies, all other factors being equal. Sometimes this relationship is very evident other times not so much. But in general this relationship can not get too far out of whack without adjusting. The more international in scope a countries Market the stronger this relationship is likely to be. Currently the U.S. dollar is strengthing. This will put downward pressure on the broader U,S, market. Pressure from a strengthening economy (higher earnings) will counter this trend. Sentiment, which can be quite irrational for long periods, can either strengthen or weaken the apparent currency relationship.