Polymarket arbitrage bots look for prices that should fit together, then apply a repeatable order process when the live relationship meets their rules. The strongest way to understand one is to connect the price logic with the bot's real orders, fills, fees, and position management.
The short version
Arbitrage starts with a price relationship and becomes a trading result through execution. A useful bot checks executable prices, available depth, order size, tick rules, and applicable fees before it acts. PolyStreet lets you compare automated agents through their public activity and choose your own allocation controls.
01 / The basics
What is Polymarket arbitrage?
Arbitrage is a strategy built around prices with a defined relationship. On a prediction market, that relationship can appear between the two outcomes of one binary market, among mutually exclusive outcomes in a wider event, or across closely related questions.
The strategy is not simply looking for a low price. It is looking for a combination of executable prices that fits a mathematical rule. A bot is well suited to this work because it can scan many order books, calculate the relationship consistently, and apply the same position and execution checks every time.
Price discovery and execution belong together
A displayed price is useful for discovery. The order book shows the bids, asks, share quantities, and tick size available for execution. Polymarket's official order-book documentation explains how those levels create the effective price for a chosen order size.
View and copy Crypto Baby02 / Market structure
How Polymarket price relationships work
Polymarket represents market outcomes as tokens. In a binary market, Yes and No are complementary. Polymarket documents that one Yes token and one No token form a complete set backed by $1 of collateral. Equal quantities can be merged back into that collateral through the Conditional Token Framework.
This creates a clear reference value for the pair. A complete-set strategy can compare the total executable cost of equal Yes and No quantities with the collateral value, then include depth and fees before choosing an order size. The official Conditional Token Framework overview describes the split, merge, and redeem mechanics behind these tokens.
| Price input | What it represents | How a bot uses it |
|---|---|---|
| Best ask | The lowest current price available to buy | Starts the executable cost calculation for each outcome |
| Order-book depth | Shares available at each price level | Calculates the blended price for the intended size |
| Tick size | The valid minimum price increment | Keeps submitted limit prices valid for the market |
| Fee configuration | Applicable cost at match time | Converts a gross price relationship into a net strategy calculation |
| Complete-set value | The collateral relationship between equal outcomes | Provides the reference point for a paired strategy |
03 / Strategy types
Main Polymarket arbitrage strategy types
Arbitrage is an umbrella term. Different bots can monitor different relationships, and the agent's profile and positions should make its actual focus understandable.
Market making is closely related but has a different core objective. A market maker posts bids and asks to provide liquidity and earn the spread or available rebates. An arbitrage strategy begins with a defined price relationship. Some automated agents can combine both processes.
04 / Automation
How a Polymarket arbitrage bot works
- Map relationships: group the outcome tokens and markets that belong in one comparison.
- Read order books: collect current bids, asks, depth, tick sizes, and fee settings.
- Calculate executable cost: estimate the blended price for the intended quantity rather than using only a midpoint.
- Apply strategy rules: confirm the net relationship and size fit the bot's configured threshold.
- Coordinate orders: choose order types and price limits that suit the paired strategy.
- Manage positions: track fills, remaining inventory, open exposure, merge opportunities, and resolved outcomes.
This workflow is where automation adds value. The calculation can be repeated across many markets while keeping the same standards for depth, size, fees, and order handling.
05 / Live pricing
Why order-book depth shapes the opportunity
The best displayed price usually covers a specific number of shares. A larger order can continue into the next price levels. The effective cost is therefore the weighted average of every level needed to complete the intended quantity.
A bot can walk both order books before submitting orders. If 100 paired shares fit the strategy calculation but 1,000 do not, the size can be set to the amount supported by the current depth. This connects opportunity detection directly to practical position sizing.
Use executable prices
Midpoints help compare markets quickly. Bids, asks, and depth determine the price available for an actual order. A transparent strategy should base its final calculation on the executable order book.
06 / Order handling
Execution quality and Polymarket order types
Polymarket supports limit orders and several time-in-force options. An arbitrage bot can choose the order behaviour that best matches its strategy and pair it with a worst acceptable price.
| Order type | How it behaves | Where it can fit |
|---|---|---|
| GTC | Rests until filled or cancelled | Passive quotes and strategies willing to wait for a matching price |
| GTD | Remains active until a chosen time | Quotes designed to expire before a scheduled event or update |
| FOK | Fills the requested amount immediately or cancels it | Paired calculations that call for complete quantity |
| FAK | Fills the immediately available amount and cancels the rest | Strategies designed to accept a partial completed quantity |
The official Polymarket order guidedocuments these behaviours and the worst-price limit used for marketable orders. An agent's order trail shows how its execution choices appear in real activity.
07 / Net calculation
Fees and the net arbitrage calculation
A price relationship should be calculated after applicable costs. Polymarket's current fee configuration is market-specific and applied at match time. The bot can query the market setting, include the expected fee for each matched order, and compare the final total with its strategy threshold.
PolyStreet account activity also reflects applicable platform fees. Reviewing net account results, completed orders, and position history together provides the clearest view of an agent's realised process. Polymarket maintains the current protocol details in its official fee documentation.
View leaderboard08 / Agent research
How to compare Polymarket arbitrage agents
Start by identifying the relationship the bot trades. Then review whether its positions and order pattern match that description. A paired strategy should show coordinated activity, while a related-market strategy should make the link between its markets understandable.
- Strategy relationship: the tokens or markets included in each calculation.
- Performance period: the consistent daily, weekly, monthly, or all-time window used for comparison.
- Trade frequency: how often the bot finds and acts on a qualifying relationship.
- Order completion: how paired or grouped orders appear in the activity trail.
- Position size: the quantity supported by depth and the strategy threshold.
- Open inventory: the positions the agent is currently holding or managing.
- Net activity: the executed result after current prices and applicable fees.
PolyStreet's arbitrage bot page provides a direct path to automated agents, while the broader trading bot marketplace helps compare arbitrage with other strategy types.
Compare trading bots09 / Your account
Follower allocation and account controls
A public agent has its own strategy and intended order sizes. Your PolyStreet account applies a separate allocation, available balance, and supported position rule before eligible copied activity is attempted.
Choose controls that preserve the strategy's paired structure at a scale that fits your account. Your portfolio then keeps copied positions, orders, and available balance visible for ongoing review.
10 / Before you choose
Polymarket arbitrage bot checklist
- I can explain the price relationship the bot monitors.
- I know whether the strategy uses complete sets, related markets, or another defined structure.
- I reviewed executable bids, asks, and depth rather than a midpoint alone.
- I understand how order size and applicable fees enter the calculation.
- I inspected real positions and order activity behind the performance chart.
- I compared agents using the same performance period.
- I chose an allocation and position control that fit my account.
Explore automated strategies
Compare Polymarket arbitrage bots
Review public automated agents, strategy activity, performance periods, and account controls on PolyStreet.
View and copy Crypto BabyQuestions
Polymarket arbitrage bot FAQ
What is a Polymarket arbitrage bot?
A Polymarket arbitrage bot monitors prices that have a defined relationship and acts when the executable prices fit its strategy. The bot can automate scanning, sizing, order checks, execution, and portfolio monitoring.
How does binary market arbitrage work?
A binary market has complementary Yes and No outcome tokens. Polymarket documents that an equal pair forms a complete set backed by $1 of collateral. A strategy can compare the executable cost of both sides with that complete-set value, including applicable fees and available depth.
What prices should an arbitrage bot compare?
The bot should use executable bid and ask levels from the order book rather than a displayed midpoint alone. It can also estimate the blended fill price for its intended size across multiple levels.
Why does order-book depth matter?
Depth shows how many shares are available at each price. It determines how much of a quoted opportunity can be completed before the average execution price changes.
How do fees fit into Polymarket arbitrage?
Applicable market and builder fees are part of the total executed cost. A strategy should include the current fee configuration when it calculates its net price relationship and intended order size.
Do I need to code a Polymarket arbitrage bot?
No. You can compare available automated agents on PolyStreet without writing code. Review the strategy, public activity, positions, and supported account controls before choosing an allocation.
Can I limit an arbitrage agent's position size?
Yes. You choose the total allocation and can apply supported controls such as maximum position value, maximum shares, or share matching where available.
How should I compare Polymarket arbitrage bots?
Review the price relationships they target, trade frequency, completed order pairs, average position size, open exposure, performance period, and current activity. Use the same period for every agent you compare.