I received BPYPM from the buyout of BPY. Currently BPYPM is yielding about 10%. I have searched but with no success to find out why the yield is over 3 times the yield on 10 year treasuries. Without any other knowledge, my 10% yield is at least worth holding and perhaps adding to, but should it be a sell?

BPY has four preferred issues -- BPYPP, BPYPN, BPYPO and BPYPM. They generally yielded between 5.5 and 6.5% at the issue price, which represented a relatively cheap cost of capital for BPY. The market prices have bounced around quite a bit, from above par in mid-2021 to well below here lately, raising the yields on current cost to ~10%. Management says the distributions are well covered, they have no plans to suspend payouts, and that doing so would make it hard for them to sell preferreds in the future.

Barring an immediate need for the cash, I'm not sure why you would want to sell them at this low ebb. If one were interested in buying, now would be a good time, assuming you don't share the market's general skepticism about BPY (now the privately-held BPG). For the uninitiated, they all come with the associated K-1 reporting form, which complicates tax reporting a little and generally takes a little longer to generate than traditional tax forms and can delay the ability to file by a few weeks.

The market's opinion of BPY is well-known. It's what caused Brookfield to take it private. BPG's well-advertised plan is to redevelop and divest lower-quality assets while lowering leverage, which might improve the market opinion over time. Or not.

One of the services on Seeking Alpha recently published an interview with management specifically about the preferreds. Hoping this link gets you there (scroll past the newsletter sales pitch at the top):

seekingalpha.com - New buy alert percent dividend yield