the real issue is how the fed does it and why.
the fed’s job is to insure the dollar doesn’t deflate to $0.00 ... as such, anything that hurts the dollar is bad.
when they know some event is about to be announced (and yes, they have insider info), they buy up gold at market towards the end of the day... and the next morning dump it for a loss. this has the effect of downward momentum on gold, giving an upward momentum on the dollar. then the bad news comes out and the dollar’s momentum swings downward, back to normal.
all this costs the fed is the lost ... but that money is part of the $80b/mon (if they’re still printing it)
QE ended last October.
Bingo. What you posted is precisely the game they play.