It was a good quarter for the private mortgage insurers as most beat estimates, helped by slow loan prepayment speeds, stable margins and low loss rates from fewer defaults, a BTIG report noted.

But the good times are not likely to last, wrote Eric Hagen, in the report issued on Nov. 2 after the last four of the six companies reported results. (MGIC reported on Oct. 31 and Arch — which BTIG doesn't cover — reported earlier in the cycle).

"The growth opportunity may be somewhat limited by the fact that mortgage rates are high and affordability remains tight, although conditions in the purchase market haven't suffered significantly," Hagen said. But the industry could have "modest amounts of portfolio growth if we ballpark $270 to $290 billion (annualized) of new insurance…written at these mortgage rates."

Insurance-in-force totaled $1.55 trillion as of Sept. 30, up from $1.539 trillion three months prior. The six companies did $78.2 billion of new insurance written, versus $81.7 billion in the second quarter and $104.1 trillion for the third quarter of 2022.