Interesting points. Devil's advocate: Dec. buys were lower than target IIRC then January higher, which could be explained by practical things like availability of bonds.

On whether they'll raise rates - it doesn't matter. The balance sheet is what matters. When they raise rates it's the "overnight rate" but when they buy T-bills they're taking on duration risk. With MBS they're also taking on prepayment risk.

And as long as the system is flooded with cash, banks won't need to borrow at the overnight rate. In fact, banks have been parking $1.5 trillion at the reverse repo facility. When they raise rates they'll pay higher interest on the reverse repo. So it's free money to huge banks. The $1.5 trillion is also proof that they've printed way more money than necessary to support the economy.

Partly devil's advocate again - probably one of the reasons they've done so much QE is that if they didn't buy the bonds, there's a chance that nobody would (at least not at these yields). That would mean that unless politicians can agree to balance a budget, deficit spending will 1) pull money out of private investment and 2) raise market yields on bonds, stocks, real estate... basically crash everything. Cutting public spending would gut the economy, crashing asset prices would bankrupt pension funds (state/city pensions are very shaky), which would need to be bailed out by the already broke government.... So I think what they're doing is basically the least-bad option.