Why dont brokers have bank CDs as marginable? Seems silly. What am I missing?

Bank CDs seem pretty safe, especially when $250k and under per institution.
Why dont brokers allow them to be used as margin?
There has to be a reason but I cant think of one.

 

Maybe it’s because they can repo them out

 

The money belongs to the BANK to use not the broker.
If you buy treasuries from your broker they can sell the treasuries to cover a loss in your account.
If you buy a CD the BANK is using the money so the broker can't sell the CD to cover a loss in your broker account.

 

Margin on CDs is not an allowable asset by the Federal Reserve under reg. T

 

T-bills higher yield and good collateral.

 

liquidity really, banks can’t repo cd with the fed.