For the upcoming June report, current prepayment expectations show speeds increasing around 15% to 20% in 30-year FNMAs, and 10% to 15% in GNMAs. The expected jump is due to a higher day count, seasonals, and the increase in the Refinance Index resulting from lower rates.
Meanwhile, July speeds are expected to increase by 5%. The modest increase is due, in part, to a lower day count. August speeds are also expected to rise 10% to 15%. The strong increase is also partly related to day count - 23 days versus 20 days in July.