but after market (and pre-market) there is an auction for buyers and sellers and it matches off based on the bids and asks that take precedent to those in the queue.
Anyone in the after-market auction that bid at > 0.25 essentially ensured that their order was filled first (ahead of yours).
But because you were partially being filled before close, it means you were the first in the ordinary queue.
Tomorrow, there will be the pre-market auction, where other bidders can outbid you again, but from 10.10 you should resume to being first in queue again
SXY Price at posting:
25.0¢ Sentiment: Buy Disclosure: Held