CF Industries (CF) shares ended the last trading session 6.5% higher at $99.93. The jump came on an impressive volume with a higher-than-average number of shares changing hands in the session. This compares to the stock's 8.8% gain over the past four weeks.CF shares jumped following the Environmental Protection Agency's new proposal to boost biofuel blending mandates, expected to benefit biomass-based diesel production. Being among the largest ammonia producers globally, CF will benefit from this initiative ...