The most important chart to look at right now is one of the broad market -- and the SPDR S&P 500 ETF ( SPY) is the best way to do that. It doesn't take an expert technical analyst to see what's going on in SPY right now; one glimpse at this chart should be enough to figure out that the big index is in a super-orderly uptrend right now, and it has been since all the way back in November. >>5 Rocket Stocks to Buy as the S&P Rebounds SPY's price action yesterday gave us another big breakout for the index, a move through all-time highs that has a way of creating a positive feedback loop for investors. Think of it this way: Almost everyone who owns a diversified portfolio of stocks is sitting on gains right now -- and investors who sold their equity positions off early have missed out on a massive multi-year rally. That fact should help move some money from the sidelines (where retail investors are sitting en masse) and back into the equity market in 2013. If you're looking to build a position, the most tactical time to be a buyer is on a bounce off of support -- and that's exactly where SPY is sitting right now. The uptrend in relative strength is another telling piece of the puzzle in the broad market. While SPY is supposed to track the S&P 500 index very closely (in a perfect world, that relative strength line below the price chart should be flat), the uptrend suggests that investors are trying to go overweight into equities as a group even while some of the biggest names on the market continue to perform poorly. SPY, after all, is one of the easiest ways to go "long the market," so when it sees positive relative strength versus the S&P, it's a constructive signal for stock prices. Investors who aren't building an equity position right now may wish that they had been.