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I would like to discuss the methodology of order filled in this topic For example, ES (Futures of S&P 500) current price is 1234. John places five (long) limit orders at 1200 at 1:30pm. Mary places one (long) limit order at 1200 at 1:35pm. Suppose ES goes down, "touches" 1200 and goes up again. (1) Will John's five order be filled first because he placed order earlier than Mary? (2) Does the filling methodology depend on TIME (assume SAME price) only? (3) Does it also depend on QUANTITY? Or any other factors? Thanks a lot.