New Margin Calls Could Sink Thornburg

Updated from 12:22 p.m. EST

Shares of Thornburg Mortgage(TMA Quote) plummeting more than 60% to well below their 52-week lows, after the jumbo mortgage lender on Monday said new margin calls could spell its demise.

The Santa Fe, N.M.-based lender on Monday said it faces $270 million more in margin calls on top of the $300 million it disclosed last week. If it wasn't able to pay the calls, Thornburg may have to sell the pledged securities at a discount

"Such an occurrence would have a material adverse effect on the Company's ability to continue its business in the current manner," the company said in a statement. ...