The average daily trading volume in agency MBS fell to $185.1 billion in May, the lowest reading of the past 17 months, according to the Securities Industry and Financial Markets Association. Year-to-date, the average is still ahead of last year’s pace but not by much: $204.2 billion compared to $201.9 billion for 2016. But these are interesting times for investors as both bonds and stocks continue to rally near new highs. Earlier this week, the yield on the benchmark 10-year Treasury fell to 2.12 percent, the lowest reading since the November election. It’s...