FHA volume in Ginnie Mae mortgage-backed securities rebounded in April because of the agency’s price cut in late January and improvements in the economy, according to industry participants. Recent data from the FHA show a sharp uptick in refinance business, which jumped from $2.29 billion in endorsements in February to $8.15 billion in March. Total FHA forward-mortgage business rose by 83.8 percent from February. The surge came...