A generally firmer Dollar and Yen, and a souring in risk appetite, will greet U.S. market participants as they return to their desks from their long weekend. USD-JPY edged out a three-day low of 109.32, driven by Yen outperformance as forex markets week looking for safe havens. Europe and Asian stock markets came under pressure, and S&P 500 futures racked up a 0.8% loss in overnight trading, pointing to a hefty opening loss on Wall Street later. The cash version of the S&P 500 had closed on Friday with a 1.3% gain.