Up first, it makes sense to take a closer look at what's going on in the big picture: the S&P 500. To make it tradable, we'll use the SPDR S&P 500 ETF ( SPY) as our proxy. At first glance, you don't have to be an expert technical trader to figure out what's going on in the big index; the S&P uptrend is still very much intact this month. >>5 Stocks Set to Soar on Bullish Earnings It's just not the same uptrend that SPY was in back at the start of the summer, but that's OK. While SPY may not be moving up at quite the same pace that it started at, the fact that this ETF is making higher highs and lows comes without question. Earnings season started on July 8, and as you can see from the chart above, the S&P has basically been consolidating sideways ever since. Consolidations are healthy for stock rallies, giving traders a chance to catch their breath and establish a base, and with earnings season ending, the uptrend looks likely to resume. When stocks are trending higher, there really isn't a bad time to be a buyer -- but there is an optimal time. That optimal buying point comes when SPY bounces off of trendline support. Buying off a support bounce makes sense for two big reasons: it's the spot where shares have the furthest to move up before they hit resistance, and it's the spot where the risk is the least (because shares have the least room to move lower before you know you're wrong). That's when I'd suggest picking up shares of this ETF.