FMCKJ has been blowing up for the past 10 days or so ($2.15 at the moment, same $25 redemption, much higher divvy). FMCKJ and FNMAS are usually the first two movers. They are the most liquid $25 preferreds. When a move happens, it's those two first, then the other $25s, then the $50.
Could be seeing a nice upswing in the coming days.