10 and 3 yesterday, 10 awarded 4.36, today 10 is 4.41, that’s 50bps diff. not usually but can be manipulated in dutch auction. once your name is in there, you can’t withdraw. if foreign buyers put in 4.5% and clear only small amount, prime brokers can submit the last bid at lower yield therefore everyone gets the last price. prime brokers brokers can access the fed window to pawn it back, while foreign non banks cannot.