Up first is shoe and apparel retailer Foot Locker ( FL). Foot Locker has actually managed to more or less keep pace with the S&P this year, turning out gains of 7% since the first trading session of 2013. But it's the trading setup in shares that gives this stock its toxic status. Right now, Foot Locker is forming a bearish descending triangle pattern, a price setup that's formed by a downtrending resistance level above shares and horizontal support below them. Essentially, as FL bounces in between those two technically significant price levels, it's getting squeezed closer and closer to a breakdown below that support level at $31.50. When that happens, we've got a sell signal for shares. It's worth noting that FL's sell signal is conditional. Toxic though this stock may be, if buyers can take control of FL, it could avoid generating a sell signal. That said, momentum, measured by 14-day RSI, is on the side of sellers. The momentum gauge has been in a downtrend since August. Since momentum is a leading indicator of price, that doesn't bode very well for FL.