As per my experience so far, I must say it's really uncertain to predict the market, since 3 months I've seen many ups and down. Still I'm on DYOR(Do Your Own Research) thing. Best time to invest is unpredictable. Follow some criteria, pick top 50 or 25 or less and play with them, analyse the graph, acquire when it falls down, sell when you get 10%+ profit, make use of stop and loss effectively.