Political risk. Cameco had to sell its gold reserves in the Kyrgyz Republic because of pressure from its autocratic government. It is currently renegotiating its contract with Russia for buying uranium from dismantled Soviet era submarines, presumably at a lower price. This affects Cameco's costs and ultimately lowers its profit margin.
Coal Power. Coal demand has been surging in the past six months. Low prices, coupled with a cheap dollar, has lead an increase in coal power as a share of US and global electricity generation. As Clean Coal progresses, the premium paid for nuclear energy may not seem as attractive.