Shares of truck trailer manufacturer Wabash National Corporation (NYSE: WNC) are up 10% as of 11 a.m. EDT today. The reason for the gain comes from the company's after-market earnings announcement yesterday that was better than expected and management's decision to raise guidance for fiscal 2017.Despite missing on both revenue and EBITDA expectations, Wabash was able to beat predictions for earnings per share by posting a normalized result of $0.31 per share.