[A]t this point, Radian looks like the better bet than MGIC. For one thing Radian has two business lines rather than one. Moreover, MGIC's dollar-loss per claim is going up faster than Radian's. That's because Radian shrewdly capped its loss exposure on its Alt-A mortgages to just 14% of the unpaid principal, while MGIC is paying out on over 27% of Alt-A mortgage losses. What makes that category so lethal is the fact that the size of these generally "no documentation" mortgages is so much larger than subprime mortgages.
~ Barron's, "MGIC, Radian Offer a High-Wire Act," October 29, 2007, by Jonathan R. Laing