They are not separate things. It is not a coincidence. However, you are not taking into account the very real difference in the composition of the balance shee

They are not separate things. It is not a coincidence. However, you are not taking into account the very real difference in the composition of the balance sheet. Buying a short-term risk free instrument (and thereby expanding the balance sheet) in order to increase liquidity in that market is very different from what was happening during QE.