The clock is ticking on the phrase-out of the London Interbank Offered Rate, or LIBOR, a benchmark the mortgage market has relied on for the past few decades. Now comes the debate: is it something to worry about or no big deal? A new report from Bank of America Merrill Lynch suggests that when it comes to MBS at least, the changes will be felt, depending on the sector. “Certain agency MBS cash flows will be impacted directly,” BAML notes. “For example, underlying cash flows on LIBOR-indexed hybrid ARMs may change if an alternate index is chosen.” The researchers noted...