The reviewer in the middle.
PropArbiter is an independent audit service for proprietary trading. We check a funded account against the firm's own published rules, look at how the profit was made, and issue one report that the firm and the trader both receive.
Why we exist
Every payout in prop trading is a judgement call, and today it is made by the party that has to pay. Firms review accounts quickly, with partial tools, and sometimes pay accounts that broke their rules. Traders who are denied cannot see the evidence and take the argument to Discord and Trustpilot. Both sides lose, and neither can prove anything.
An independent reviewer with nothing to gain on either side removes that problem. That is the whole idea.
What we do
- Rule replay. We import the rules a firm already publishes, the firm confirms them, and we replay every one across the full history of an account: minimum trading days, consistency, lot sizes, risk per position, weekend holding, news windows.
- Trade forensics. We look at how the money was made: latency arbitrage against the firm's own feed, copy trading and group accounts, martingale and high-frequency patterns.
- One report for both sides. Every rule answered, the sentence it came from, the trades behind each answer, and a public link that proves the document has not been edited since it was issued.
- Published rules pages. The rules we check are the rules the trader reads. One document, not two kept in step.
What we are not
We are not a broker, not a prop firm and not a CRM. We never hold, release or block a payout. We do not connect to a firm's platform, and we never ask for anything beyond read-only credentials. Daily loss, drawdown and profit targets stay with the firm's own risk system, which already watches them live.
How we stay neutral
- Deterministic verdicts. Pass and breach come only from a rules engine executing a versioned rule set. Language models write the explanation; they never decide.
- Symmetric rigour. A clean account is cleared with evidence, not with silence. The same check that flags a trader also clears one who was accused wrongly.
- Immutable reports. Once issued, a report is never edited. A correction is a new, linked report.
- Undecidable is an answer. When the data cannot support a verdict, the report says so rather than guessing.
- Private by default. Reports are private. Publication is per report, opt-in, anonymised and revocable.
Where we are going
We started with MetaTrader 5 and firm-facing payout reviews. cTrader and Match-Trader follow, then verified firm profiles and a public directory of opted-in reports. If you run a firm or trade for one and want to shape that order, write to us.