The complaint arrives in the same shape every time. A trader clicks at 1.0842, the fill prints at 1.0844, and the conclusion is that the broker moved the price. Sometimes that is exactly what happened. Far more often the market moved in the 80 milliseconds between the click and the fill, and the only way to distinguish the two is measurement across a sample, not a screenshot of one order.
What you are measuring
Slippage is the signed difference between the price you asked for and the price you received, expressed in pips or in the instrument's tick. Sign matters. Positive slippage, a fill better than requested, is real and happens on genuinely neutral execution roughly as often as the negative kind. A broker whose statistics show negative slippage on almost every order and positive slippage on almost none is telling you something, and it is not that the market is unlucky.
The distribution is the point. Any single fill is noise. Two hundred fills grouped by instrument, by session and by order type produce a shape you can actually read, and the mechanism behind the numbers is in slippage explained.
Where the data comes from
Three sources, in descending order of quality. The best is the platform's own order log, which records the requested price, the executed price and the timestamps for each stage. MetaTrader writes this into the journal and the deal history, and it can be exported. A newer web terminal usually exposes the same fields in an account statement or an API.
The second source is a trade copier or bridge sitting between you and the broker, which sees both sides and can log the difference directly. That is how firms audit their own routing, and the general architecture is in platform bridges explained.
The third is a journalling application that reads your statement and computes the gap. Convenient, and only as good as the fields the statement carries. If the export does not include the requested price, no tool can reconstruct it, and a journal that shows only entry price is measuring nothing about execution. The comparison of that category is in trading journal apps.
Slippage measured without a matching timestamp is unusable. A fill two pips away from your click is normal at 15:30 on a payrolls day and unusual at 03:00 on a Tuesday, and the number alone does not tell you which one you are looking at.
The comparisons that actually mean something
Group your fills four ways and the picture separates quickly.
By order type. Market orders slip. Limit orders do not, by definition, because a limit either fills at its price or better or does not fill. Stop orders behave like market orders once triggered, which is why stop losses slip during gaps and why a stop is a request rather than a guarantee, as covered in stop loss strategies.
By time of day. Fills at the London and New York session overlap should be tighter than fills at the Asian open on a minor cross. If yours are not, the problem is liquidity on your instrument, not the broker's intent. Session behaviour is in forex trading sessions.
By event. Tag every fill within a few minutes of a scheduled release. Those belong in their own bucket, because a two pip slip on a rate decision is the market working normally and averaging it into your ordinary statistics ruins them.
By direction. This is the one that catches genuine execution problems. If buys slip against you and sells do not, or vice versa, you are looking at a systematic skew rather than market noise.
Requotes are a different measurement
A requote is not slippage. The order was rejected and offered back at a new price, so nothing filled and there is no gap to measure. Requotes need their own counter, because a platform that never slips but requotes constantly is not giving you better execution, it is giving you the same cost in a different form. That distinction is in requotes and execution.
Count rejections too. A rejection rate that climbs during volatility is the same information as slippage arriving under a different label.
Reading the result without fooling yourself
Two mistakes are common. The first is a sample of thirty trades, half of them around news, concluding the broker is dishonest. The second is comparing your fills to a chart from a different price feed, which will differ by a fraction of a pip at any moment for perfectly ordinary reasons.
What a clean audit gives you is leverage in a conversation. Regulated firms operate under best execution obligations and publish policies describing how they route orders, so a documented pattern of one sided slippage on a specific instrument is a question worth putting to them in writing rather than a complaint in a forum. The framework is in best execution rules.
The other use is your own strategy. If a system's edge is a pip and a half and your measured average cost is a pip and a half, the audit has told you something more useful than any broker comparison: the strategy does not survive its own execution costs, and no amount of platform switching fixes that.
"One bad fill is a story. Two hundred fills sorted by direction and time of day is evidence. Traders bring me the story and I ask for the spreadsheet."
— Alex Onta, Executive Director, SINGUARD
Key Takeaways
- Measure the signed gap between requested and filled price with timestamps, then read the distribution rather than any single fill.
- Positive slippage should appear regularly on neutral execution, so an almost entirely one sided record is the signal worth investigating.
- Group fills by order type, session, scheduled event and direction, because a systematic skew by direction is what separates execution problems from market movement.
- Requotes and rejections are a separate count, since an order that never filled has no slippage to measure but carries the same cost.
Frequently Asked Questions
What is a normal amount of slippage?
There is no universal figure. It depends on the instrument's liquidity, the time of day, the order size and whether a scheduled release is in progress. The useful comparison is your own record against itself: fills at the London and New York overlap should be tighter than fills on a minor cross at the Asian open, and both should show positive as well as negative slippage.
Does positive slippage really happen?
Yes. On neutral execution a fill better than the requested price occurs about as often as a worse one, because price moves in both directions during the milliseconds between request and execution. A record showing almost no positive slippage over a large sample is the pattern worth raising with the provider.
Can I track slippage without special software?
Yes, if your platform exports both the requested and the executed price with timestamps. MetaTrader writes this into its journal and deal history, and many web terminals expose the same fields through a statement or API. A spreadsheet grouped by order type, hour and direction covers most of what a paid tool would show you.
About the Author
Alex Onta is an Executive Director at SINGUARD. He built eTrader, the terminal, the mobile apps, eTrader Broker, Copytrading, Business and Community, along with the worldwide clustered-server infrastructure it all runs on, with his brother Roman Onta helping on the design, and he leads that division today. Together with Roman he builds the Prop Firm CRM, the Broker CRM, Scalegram and CopySignals, and the two of them carry worldwide compliance, payment processing and international business structuring side by side. He lives and works in Dubai for most of the year. Meet the executive duo leading Singuard's five divisions.