Hi Greg,
Many many, many many, years ago I traded MBS's. I am not sure you have the bond thing right. When interest rates rise, the existing bond portfolio can only be sold at a discount because current and future book has a higher yield. The converse, when interest rates fall, the existing past book can sell at a premium, provided it has a performance history (not including sub-prime).

It is my understanding, that since around 2008-2009, the Fed has been buying most of the MBS market, since no one else, of right mind would buy one. It is a "Catch 22"; when the Fed raises interest rates, it is discounting its own book of MBS; the more rates rise, the low the price of existing MBS.

I would be more than happy to discuss this with you in greater detail, off post. On a side note - everything at this point is manipulated, especially metals.

Personally, I am not a fan of cryptos, not that some people have made "bookoo bucks". The five characteristics of money are the following, cryptos only possess one ( all things are relative to each other):

1.) Stable in Value
2.) Generally Accepted
3.) Durable
4.) Divisible
5.) Portable