BALTIMORE ( Stockpickr) -- A handful of stocks could be poisoning your portfolio right now. If you haven't prepared an antidote, you'd better read on.Too often, investors remain fixated on the stocks they should buy. Never mind the stocks they shouldn't buy -- or worse, the stocks they should sell. But ask any successful investor (be they a deep value guy or a technical trader), and they'll tell you that the key to longevity in these markets is to avoid losses. The only way to do that is by figuring out which "poison stocks" shouldn't be in your portfolio. The fact of the matter is that we're knee-deep in a pretty significant rally -- around 84% of the S&P 500's 2012 gains have come since the start of June alone -- and the names that aren't participating in it are sending a bid message to Wall Street. >>5 Stocks That Could See Major Downside To be fair, the companies I'm talking about today aren't exactly "junk." I mean, they're not next up in line at bankruptcy court. But that's frankly irrelevant; from a technical analysis standpoint, they're some of the worst positioned names out there right now. For that reason, fundamental investors need to decide how long they're willing to take the pain if they want to hold onto these firms this summer. That's why we're taking a technical look at these names today. For the unfamiliar, technical analysis is a way for investors to quantify qualitative factors, such as investor psychology, based on a stock's price action and trends. Once the domain of cloistered trading teams on Wall Street, technicals can help top traders make consistently profitable trades and can aid fundamental investors in better planning their stock execution. >>5 Big Stocks Ready to Slingshot Higher It's worth noting that some of the worst stocks on the market didn't make this list - that's because, by and large, the garbage stocks are bouncing this summer, providing shareholders with a long-awaited reprieve. And I've already identified some of the most egregious setups in the tech sector in 5 Social Networking Stocks to Sell Now. So, without further ado, let's take a look at five more "poison stocks" you should be unloading in August.