Fill Ratio

The proportion of an order that is executed versus the amount you submitted, often relevant for limit orders or partial liquidity.

1 min

Why it matters

Fill ratio affects your real exposure. Low fill ratio often triggers chasing behavior and worse average prices.

Operational use: this is how the market taxes urgency. When it appears, slow down or size down.

Common trap

Chasing the missing 70% without a plan. It turns execution into improvisation.

Example

You place a limit for 10 lots; 3 lots fill. Your fill ratio is 30%.

Operational cue: if you can’t point to it on the chart, in the DOM, or in your broker logs, treat it as a story and trade smaller.

Notes

If you see this repeatedly, you are in a different regime than your model assumes.
Regime change usually means position size change.
When in doubt: trade smaller, or don’t trade.