Unless you can pick stocks perfectly or time the market like nobody else, all you need is the following chart to become a smart investor. Buy the S&P 500 best stocks when the index bounces off of the 50 week moving average. The red line on the chart, inside the bubble is where you should buy in an uptrend. Just looking at the pattern, assuming it will continue (and it will until it doesn’t) the next buy point is probably Sept 2013.
That means you will have been in cash the whole 2013 until Sept 2013.