Jane, the idea is that the Fed buying adds to the demand and therefore prices should be stronger. They are always long, never short.
And, it's difficult for me to imagine what the buying by the Fed of bonds translates very directly into the price of individual stocks. And the kind and length of bonds. Today the notice says they are buying a small amount if TIPS which are inflation protected securities. Meaning? I dunno at all.
Some of us here pay a little attention to it, but mostly not, I believe, feeling that the particular technical dynamics of the volatile issues like TSLA, NFLX, AAPL, and AMZN are more significant in predicting the intraday movements which I and smartone, at least, trade a high percentage of the time.
Beerworld is much more steady, trading SPY I would say, 90% of his scalp attempts, mostly successful. I haven't inquired, but would guess that the POMO effect on SPY would be more likely. I do know that he has a very high percentage of green scalps doing it the way he does.
I'd welcome comments from other traders as to their opinion of the POMO effect, or lack thereof.