Impac Mortgage ( IMH) surged 45% after it sought to reassure investors that it has adequate capital should its lenders exercise margin calls. The Irvine, Calif.-based real estate investment trust said Wednesday that it does have financing facilities and continues to fund loans that are eligible to be sold to the government-sponsored agencies. The company has also made all margin calls to date. "I would like to disclose to our stockholders that this UBS analyst wrote this report without speaking to management since our earnings conference call on May 11, 2007," CEO Joseph Tomkinson said in a statement. "Further, we believe that his comments are largely speculative and are adding to the volatility of the stock price. While we can not make any guarantees, we continue to believe that we can successfully navigate through this cycle emerging as a stronger, more competitive company." But like many mortgage lenders, Impac suspended earlier this week the origination and funding of Alt-A loans -- its primary origination business -- as a result of the collapse of the secondary markets. That comes a day after a UBS analyst questioned whether Impac would be able to satisfy margin calls. Other mortgage related-companies, such as Luminent Mortgage Capital ( LUM), have been hard hit by calls for further collateral. Luminent shares were halted at midday Wednesday as questions about the company's liquidity continue to swirl.