Absolutely. The best times in any days are (in EST) are 7-11p.m., 1-4 a.m. and 6:30 a.m. to 2 p.m. Be careful on trading days after 2 as people are removing liquidity and hence the market consolidates. Observe it for a while but you`ll notice most really violent market moves occur during the first three hours f the different market openings.