Mountaineer Partners is raising capital for a fund that would pay off handsomely if Fannie Mae and Freddie Mac are released from government conservatorship next year.The New York firm hopes to assemble $100 million to invest in the shares of the two big mortgage agencies. It believes the vehicle, Mountaineer Partners GSE Opportunity Fund, could produce a return of 50-100% over the next 12-18 months. Its “bear case” projected return is...