BALTIMORE ( Stockpickr) -- How long is this rally really going to last? With stocks at four-year highs right now, investors are starting to look for the black clouds.Losses in the eurozone could drag stocks down here at home today, forcing the S&P 500 to test the strength of the 1400 level that it's been holding since Friday. While that level of selling doesn't have any longer-term implications for us, sentiment is still worth keeping an eye on this week. At this point, though, stocks are still majorly in favor, so to take full advantage, we're turning to the technicals in five of Wall Street's big-name stocks this week. >>5 Stocks Insiders Love Right Now If you're new to technical analysis, here's the executive summary: Technicals are a study of the market itself. Since the market is ultimately the only mechanism that determines a stock's price, technical analysis is a valuable tool even in the roughest of trading conditions. Technical charts are used every day by proprietary trading floors, Wall Street's biggest financial firms, and individual investors to get an edge on the market. And research shows that skilled technical traders can bank gains as much as 90% of the time. Every week, we take an in-depth look at large-cap stocks that are telling important technical stories. Here's this week's look at the technicals of five must-see stocks.