Warehouse banks that extend credit to nonbank residential lenders ended the fourth quarter with almost $40 billion in commitments on their books, their best quarter of the year, according to exclusive survey figures compiled by Inside Mortgage Finance. The top five warehouse banks – which control about half of the estimated total market – had $19.9 billion of commitments on their books, a 4 percent improvement from the third quarter. Compared to the end of March, commitments were up 37 percent. Wells Fargo, the largest buyer from correspondents, ranked...[Includes one data chart]