Closed end fund RiverNorth Opportunities Fund 6% preferred (RIV-A) went on sale just a bit ago with a mini-dump of shares. It is now trading at $22.77. This issue is rated by Moodys at A1.
For those looking for a decent yield on a very safe issue it may be worth a look, although the bid-ask spread is wide (22.7-23.49) one may not be able to secure the lowest price. Shares goes ex dividend in 10 days.