The percentage of loans paying off their balloon rate registered 59.5% in May, the second lowest of the year, but was above the 12-month moving average of 55.3%.

This was more than five points below the April reading of 64.6%, according to Trepp.

By loan count, 69.1% of loans paid off. The 12-month rolling averge by loan count is now 61.8%. 

"It might be tempting to attribute May's decrease to increasing Treasury yields and widening commercial mortgage-backed securities spreads, but that would be off base," analysts for Trepp said. 

They added, "Most of the spike in the 10-year Treasury rate and surge in CMBS spreads took place over the last two weeks, which is too recent to impact the May numbers. If we are going to see a slow down in refinancings as a result of the current conditions, we would expect to see it begin in July or August at the earliest (assuming rates and spreads don't reverse course between now and then)."