 Shares of Essent Group NYSE: ESNT gained more than 12 on Wednesday after the financial services company was added to the Standard Poors MidCap 400 index. Essent is a Bermuda-based provider of mortgage insurance, reinsurance, and risk management products. SP; Dow Jones Indices, a division of SP; Global that manages stock indexes, said after markets closed Tuesday that Essent will replace Patterson-UTI Energy in the SP; MidCap 400. 