Broker fill-quality sheet for stock scalpers

[Fairman]

Broker fill-quality sheet for stock scalpers: simple enough to finish every week.

Columns I keep:

- Date
- Ticker
- Side
- Mid at send
- Fill
- Delta in cents
- Notes (open versus midday, venue if known)

That is enough. Fancy databases can wait until the habit sticks.

Weekly review: average adverse cents versus mid by time bucket and by name. Reject or de-prioritize paths that quietly tax you at the open. If the broker won't give fill detail, that absence is a signal by itself.

A worked example of a few rows, so the sign convention is clear. Adverse means worse than mid for my side: higher for a buy, lower for a sell.

- 09:34 ET, name A, buy. Mid $48.105, fill $48.12. Delta +1.5¢ adverse. Note: open, fast book.
- 09:36 ET, name A, sell. Mid $48.265, fill $48.25. Delta +1.5¢ adverse. Note: open.
- 11:52 ET, name A, buy. Mid $48.405, fill $48.41. Delta +0.5¢. Note: midday.
- 11:58 ET, name A, sell. Mid $48.475, fill $48.47. Delta +0.5¢. Note: midday.

With just those four rows, the open costs me three times what midday does on this name. On 500 shares, 1.5¢ per side is $15 per round trip at the open versus $5 at midday. Two weeks of rows turns that from a guess into something I can act on: smaller size at the open, limit orders only in the first five minutes, or a different path for that time bucket.

How I capture mid at send without slowing down: I don't try to note it by hand in real time. I screenshot the order window or pull it from the platform's order log afterward, and fill the sheet after the close. If neither is possible, I note the bid and ask as closely as I can and mark the row "approximate."

Failure modes:

- Only logging trades I remember, which skews toward the bad fills.
- Mixing limit and marketable orders in the same average. Split them.
- Comparing brokers across different weeks, where the tape was different.

When not to bother: if you're placing a few trades a week with small size, get the setups right first. The sheet earns its keep once size and frequency make a cent matter.

This pairs with DMA versus PFOF arithmetic. You need your numbers, not a marketing PDF. Two weeks of honest mid-to-fill logs on the tickers you actually trade will teach more than a month of broker comparison threads.

Diagram: the sheet header + reminder.