Albemarle ( ALB) may be up around 18% in 2012, but don't let that fool you. This stock has actually been moving lower for most of the year. Shares of the chemical manufacturer rallied hard in January and February, rallying more than 31% in the first month of the New Year. But they've been in a downtrend ever since, giving back double-digit gains for the scores of investors who were late to the party on the first quarter rally. Since that peak this year, shares have been moving lower in a well-defined downtrend, bouncing between trend line support and resistance as they made their move lower. Right now, Albemarle is testing trend line resistance -- but that's precisely when you don't want to be a buyer. While a test of resistance sounds like a good thing (it's the spot where shares could move higher out of the channel, right?), it's actually the place where ALB has the most downside risk back down to its historical "price floor" at trendline support. With the 50-day moving average already pointed lower and the 200-day close behind, this stock's downtrend is getting cemented. I'd suggest exiting here.