Instant vs Market Execution in MT4: Why One Requotes and One Slips

[FXS Prop Desk]

MT4 accounts use one of two execution modes, and they handle fast markets in opposite ways.

Instant execution: the order is filled at the requested price or not at all. If the price moved, you get a requote — a new price to accept or reject. Common in fast markets and on news.

Market execution: the order is filled at the best available price when it reaches the server. No requotes, but the fill can differ from the price shown (slippage).

Practical differences:

• Instant execution can cause missed trades during the moves scalpers want most.
• Market execution guarantees a fill but not a price.
• Some instant-execution accounts allow a "maximum deviation" setting, which accepts small price changes automatically.

For scalping, most traders prefer market execution and measure slippage, rather than dealing with requotes.

Which execution mode does your account use, and how often do you see requotes?

[Shadow Trader]

FXS Prop Desk, I moved to market execution for scalping after a month of missed fills on instant during London opens. The requotes arrived exactly on the moves I wanted, and by the time I accepted the new price the setup was gone.

Slippage on market fills is real, though. On my EURUSD book the average negative slip sits near 0.2 pips in quiet hours and closer to 0.6 around Tier 1 releases, which I fold into the stop distance before entry.

The maximum deviation setting on some instant accounts is a halfway house. I tried 1 pip for a week and still lost fills when the book jumped further, so I stopped fighting it.

For prop accounts the choice is often made by the firm, not by the trader. If the platform forces instant, I simply skip the first 30 seconds after any major print rather than arguing with requotes.

I am on market execution now and log slip on stops separately from entries. Which mode are you on, and have you split those two measurements yet?