01Introduction
Probio Markets lets people take positions, including leveraged positions, on the outcomes of real-world events. That only works if prices are honest, outcomes are not interfered with and the platform behaves the same way for everyone. This policy sets out the conduct we prohibit to protect fair pricing, market integrity, other customers and the stability of the platform.
It explains, in plain English, each prohibited activity with an example, why it is prohibited and what may happen if it occurs. It also sets out what remains allowed, the limits every account trades within, how we investigate, and the main risks of trading on Probio.
This policy forms part of, and should be read with, our Terms of Use (probiomarkets.com/terms-of-use). If the two ever conflict, the Terms of Use apply.
02Why restrictions exist
Leveraged prediction markets combine several risks that ordinary trading does not. Many event markets are thinly traded, so a single large order can move the price. Outcomes are decided by real-world facts and by the people and data sources that report them, which creates room for interference and for unfair informational advantages. Leverage multiplies both gains and losses, and a market can jump straight from one price to another when news breaks, skipping the point at which a position would normally be liquidated.
These restrictions protect honest traders from being traded against unfairly, protect anyone who provides liquidity or capital to the platform from losses caused by abuse rather than by genuine market risk, and protect the systems that hold customer balances from being exploited. They are not designed to stop people from trading well or making money.
03How Probio prices and settles trades
Some of the rules below only make sense against how the platform works, so in summary:
- Prices: Market prices, order books and resolution data come from Polymarket's public data feeds. Probio is not affiliated with, endorsed by or operated by Polymarket.
- Execution: Live orders do not go to Polymarket. They are filled against your Probio account balance at a price we calculate by walking the public order book at the moment your order arrives. Probio is therefore on the other side of your position.
- Funds: Deposits are credited to a single USD balance held by Probio on your behalf. Withdrawals are reviewed before they are paid.
- Settlement: When an event is resolved, open positions settle at the final outcome reported by the data source for that market.
Because fills, marks and settlement depend on data we receive rather than create, errors or delays in that data, or in our own systems, can produce prices that are plainly wrong. The sections on platform vulnerabilities and erroneous trades explain how those are handled.
04Prohibited activities
The following are prohibited. Each heading covers attempts and arrangements to do the same thing, as well as the completed act.
Insider trading and material non-public information
What it is. Trading on an event while you hold material, non-public information about its outcome that you obtained or are using improperly. This includes: (1) trading while you hold confidential information about the outcome in breach of a duty of trust or confidence you owe someone, such as an employer, client or public office; (2) trading on such information passed to you by someone who owed that duty, where you know or have reason to know they could not trade on it themselves; and (3) trading on an event whose outcome you are in a position to decide or materially influence, such as being a participant, official, decision-maker, employee or contractor of an organisation involved, or a person responsible for reporting or resolving the outcome.
Example. An election official buys "Yes" on a recount market the day before the confidential result is announced; a team employee bets on a line-up announcement they helped prepare; a juror trades on the verdict of their own trial.
Why it is prohibited. Other traders cannot compete with someone who already knows the answer, and markets become a way to monetise leaked or privileged information rather than to price uncertainty.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities.
Making money is not evidence of insider trading. Good research, fast reading of public news, expertise and luck all produce profits. We look at how information was obtained and whether the trader had a duty, role or influence that makes using it improper.
Oracle and settlement manipulation
What it is. Any attempt to influence how an event turns out, or how its result is recorded, in order to profit from a position. This includes interfering with the data sources and processes that report outcomes; corrupting, falsifying or deliberately misreporting resolution data; manipulating upstream information sources that a market relies on; bribing, coercing or otherwise interfering with people involved in an event or its resolution; deliberately submitting misleading settlement information; and knowingly exploiting a discrepancy between the real outcome and the recorded settlement.
Example. Paying a referee to influence a match you hold a position on; publishing a false official-looking statement to trigger an early resolution; holding a position you know will settle on a reporting error and taking steps to keep the error in place.
Why it is prohibited. Settlement is the moment every position is paid. If outcomes or reports can be bought or bent, no price on the platform means anything.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities. Conduct of this kind may also be a criminal offence.
Wash trading and artificial activity
What it is. Trading that creates a false picture of activity, price or interest rather than taking genuine market risk. This includes trading with yourself or with accounts you control to generate volume; coordinated trades with others to create false activity; fictitious or pre-arranged transactions; spoofing and layering (placing orders you intend to cancel before they fill, to mislead others about demand); deceptive order patterns; collusive arrangements to move prices or volume; and trading designed mainly to farm rewards, cashback, referral payments, leaderboard positions or other incentives.
Example. Repeatedly opening and immediately closing positions with no market view in order to accumulate fee cashback or rise up a volume leaderboard; two friends trading back and forth to inflate a referral reward.
Why it is prohibited. Artificial activity misleads other traders about where the market really is and drains incentive programmes that exist for genuine customers.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities. Rewards, cashback or referral payments obtained through the activity may be cancelled or recovered.
Legitimate market making, providing two-sided prices with genuine intent to trade, is not wash trading.
Exploiting platform vulnerabilities
What it is. Knowingly taking advantage of a defect in Probio's systems instead of reporting it. This includes software bugs; incorrect balances, margin or fee calculations; flaws in the liquidation engine; incorrect oracle, mark-price or settlement calculations; crediting errors that pay out twice; defects in authentication or authorisation; race conditions in order processing; and trading on quotes you know to be stale or erroneous where doing so breaches these rules.
Example. Discovering that submitting two orders at the same instant lets you exceed your balance, and doing it repeatedly; noticing that a market is marked at a price that has not updated for hours while the real market has moved, and trading against the stale mark to extract a guaranteed profit.
Why it is prohibited. Profits taken from a defect are not the result of trading skill or market risk. They come out of the platform and, ultimately, out of other customers.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities. Trades that resulted from the defect may be corrected or cancelled (see "Erroneous trades and technical errors").
Ordinary arbitrage, buying where a price is lower and selling where it is higher, is allowed. It becomes a problem only together with something more: knowledge that the price is the product of a defect, or conduct designed to cause or prolong one. If you find a bug, please report it to compliance@probiomarkets.com. Good-faith reports will not be treated as misconduct.
Circumventing position and exposure limits
What it is. Deliberately getting around the limits every account trades within, for example by spreading positions across several accounts you own or control, coordinating with others to act as one, using multiple wallets or identities, or automating orders to defeat the checks.
Example. Opening $5,000 positions on the same event from three accounts you control, or asking friends to open positions on your behalf with your money.
Why it is prohibited. Limits keep any single person's exposure to an event within what the platform can safely carry. Splitting exposure across accounts recreates exactly the risk the limits exist to prevent.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities. Accounts we have confirmed, on reliable evidence, are controlled together may have their limits applied jointly.
Abusive latency and execution strategies
What it is. Deliberately exploiting a known defect in our platform, a compromised or malfunctioning data feed, or an error in our execution systems to obtain prices or fills that the published rules would not give you.
Example. Using a feed you know is delayed or broken to trade against our prices before they correct; deliberately triggering an error state in order processing to obtain a better fill.
Why it is prohibited. These strategies take value from the platform and other customers through a malfunction rather than through a better view of the market.
Possible consequences. Investigation; cancellation of open orders; a pause on opening new positions; correction of affected trades where the Terms allow; recovery of profits shown to come from the conduct; suspension or closure of the account; and, where the law requires or allows, referral to the authorities.
Fast trading, price discovery, cross-market arbitrage and hedging are not prohibited simply because they are fast or profitable. Where we can, we rely on objective, technically verifiable facts, such as whether a quote was demonstrably stale or a system was demonstrably malfunctioning, rather than on the outcome of a trade.
Other prohibited conduct
- Market manipulation: Any conduct intended to move a price away from where genuine supply and demand would put it, including attempts that do not succeed.
- Fraud: Deceptive or fraudulent trading activity of any kind, including against other users or Probio.
- Financial crime: Money laundering, terrorist financing, sanctions evasion, or using the platform to move or disguise the proceeds of crime.
- Jurisdiction: Accessing trading from a restricted jurisdiction, including through a VPN or a third party, or trading on behalf of someone who is restricted.
- Unauthorised access: Accessing accounts, systems or data you are not authorised to access, or testing our security without permission.
- False information: Giving deceptive identity, residence or account information, or opening accounts in another person's name.
- Collusion: Working with others to get around any restriction in this policy or the Terms of Use.
05Permitted trading practices
We do not generally prohibit, and do not treat as suspicious on their own:
- Profitable trading, including consistently profitable trading.
- Good-faith arbitrage between Probio and other venues, or between related markets.
- Hedging an exposure you have elsewhere.
- Market making with genuine intent to trade.
- Algorithmic or automated trading that respects the platform's limits and rules.
- Trading on information that is public, or that you obtained lawfully through your own research and analysis.
All trading remains subject to the platform's ordinary risk controls, the limits below and applicable law.
06Position limits
Every live position is limited to $5,000 of notional value. Notional is the initial margin you commit multiplied by the leverage you choose. The higher the leverage, the less margin a single position can use:
| Leverage | Maximum initial margin | Maximum notional |
|---|---|---|
| 1× | $5,000 | $5,000 |
| 2× | $2,500 | $5,000 |
| 3× | $1,666.66 | $5,000 |
| 5× | $1,000 | $5,000 |
| 10× | $500 | $5,000 |
Per-event exposure limit
Separately, your total exposure to any one underlying event is limited to $5,000 of notional. An event can contain several markets (for example, one market per candidate in an election). We add up the notional of all your open positions and all your resting limit orders on every market in that event, on both the Yes and No sides, and an order is accepted only if the total stays within the limit.
Opposite positions are not netted against each other. A Yes on one market and a No on another market in the same event can be the same bet, and even genuinely opposite positions still carry settlement, liquidity and margin risk. Resting limit orders count from the moment they are accepted, because they can fill at any time.
Both limits are checked on our servers at the moment an order is accepted, inside the same step that reserves your balance, so sending several orders at once cannot get around them. An order that would breach a limit is refused with a message explaining which limit and how much room is left. Positions opened before these limits took effect are not closed, but count toward the per-event total for new orders.
Where we have confirmed, on reliable evidence and after review, that several accounts are controlled by the same person or are trading together, we may apply these limits to those accounts jointly. A confirmed link can be disputed through support, and is reviewed if new information shows it is wrong.
Parlays are not leveraged and are not included in the per-event total. They are limited separately by a maximum payout per slip, shown when you build one.
07Price-impact protections
Before a market order is filled, we estimate the average price you would pay by walking the current public order book for the full size of the position (margin × leverage). If that estimate is more than 5% worse than the best available price, the order is refused rather than filled. The same check applies when a resting limit order is about to fill: it fills only when the estimated price is at or better than your limit and within the same tolerance.
This exists so that a single order cannot push a thin market to a price that does not reflect real trading, and so that you are not filled far from the price you saw. It is a protection, not a promise. It does not guarantee that your order will be filled, that it will be filled at the displayed price, or that a position can be closed or liquidated at any particular price. Prices can move between the estimate and the fill, and markets can gap past stop-loss or liquidation levels.
08Investigations and enforcement
How we detect potential issues
We monitor trading for patterns that can indicate prohibited conduct, such as repeated attempts to exceed limits, rapid round trips that look designed to farm incentives, large positions opened shortly before an event settles, outsized gains from very short-lived positions, and different accounts funded from the same source. We also act on reports from users and third parties.
A pattern is a reason to look, not a finding. Our automated checks create review records for a member of our team to examine; they do not decide that anyone has broken the rules. Most alerts turn out to be legitimate activity and are closed without any action.
What happens during a review
- Evidence: We preserve the relevant records: orders, positions, transactions, timestamps, account and market identifiers, and how the activity was detected.
- Questions: We may contact you for information or an explanation. Responding helps us resolve reviews quickly and fairly.
- Interim measures: While a review is open we may cancel unexecuted orders and pause the opening of new positions. Where legally permitted and approved through our internal controls, we may also temporarily hold withdrawals involving disputed amounts. You can still close existing positions and contact us.
- Decision: Decisions are made by an authorised member of staff, recorded with reasons, and communicated to you where the law permits.
Possible outcomes
Depending on what the review establishes, and in proportion to it, outcomes can include: no action; a warning; correction of erroneous trades; cancellation of rewards, cashback or referral payments obtained improperly; recovery of profits shown to be directly attributable to prohibited conduct; recovery of losses the conduct directly caused, where legally recoverable; suspension or closure of the account; and referral to law enforcement or regulators.
Treatment of funds
We distinguish between disputed proceeds (amounts that a review indicates came from prohibited conduct), your own deposits, and unrelated balances. Any withholding or recovery is limited to amounts directly attributable to established prohibited conduct, and only to the extent permitted by applicable law. Legitimate deposits and unrelated balances remain yours. If an account is closed, remaining funds that are not subject to a lawful hold or recovery are returned to you, subject to our standard withdrawal checks and any legal obligation to retain or report them.
If you disagree with a decision you can ask for it to be reviewed by writing to compliance@probiomarkets.com. Our complaints process is described in the Terms of Use.
09Erroneous trades and technical errors
Occasionally a system fault, a data-feed error or an incorrect calculation produces a trade, mark, liquidation or settlement at a price that is clearly wrong. When that is demonstrably the case, we may correct the trade to the price it should have had, cancel it and reverse its balance effects, or re-run the affected settlement. We do this whether the error favoured you or us.
We aim to identify errors promptly, to notify affected customers, to apply corrections consistently to everyone affected, and to record what was changed and why. Corrections are limited to what is needed to put affected positions where they would have been without the error.
10Reporting suspicious activity
If you see something that looks like manipulation, insider trading or abuse, or you find a bug or security weakness, email compliance@probiomarkets.com with as much detail as you can (markets, times, account names or transaction references). Reports are treated confidentially and reviewed by the same process as our automated alerts.
11Risk disclosure
- Leverage: Leverage of up to 10× multiplies losses as well as gains. A small move against a leveraged position can lose the entire margin committed to it.
- Liquidation gaps: Positions are liquidated when the market reaches the liquidation price, but prices can jump past that level when news breaks or liquidity disappears. You may lose your entire margin, and stop-loss and take-profit orders may fill at worse prices than you set, or not at all.
- Liquidity: Many event markets are thin. Orders may be refused, filled at worse prices than displayed, or be impossible to close quickly.
- Settlement: Outcomes are settled from data reported by third parties. Resolution can be delayed, disputed, ambiguous, or different from what you expected, and markets can be voided or resolved in ways you consider wrong.
- Counterparty: Probio fills live orders against its own balance sheet. Your ability to be paid depends on Probio's ability to meet its obligations. Customer balances are not insured or protected by a deposit guarantee scheme.
- Loss mutualisation: Probio does not currently share losses from one customer's positions among other customers. If that ever changes, we will explain it in advance in the Terms of Use.
- Account restrictions: Accounts can be restricted, and orders refused or cancelled, under the Terms of Use and this policy, including during reviews.
- No guarantees: Nothing on Probio guarantees a profit, a fill, a price or the availability of the platform. Only trade with money you can afford to lose.