Polymarket Grid Order: Grid Trading on Prediction Markets
Polymarket does not offer a native grid order. It supports only limit and market (marketable) orders, so laddered grid trading has to be built with an automation layer such as Hey-Traders. A grid places a series of buy and sell orders at evenly spaced price levels, aiming to profit from repeated moves inside a range rather than a single directional call.
What is a grid order on Polymarket?
A grid order is an automated strategy that places multiple laddered orders across a defined price range. As price falls it fills buys at lower levels; as price rises it fills sells at higher levels, capturing the spread between rungs. Polymarket has no built-in grid, so on Polymarket a grid is created by an external tool like Hey-Traders that submits and manages the child orders for you.
Because Polymarket share prices move between $0.00 and $1.00 (representing implied probability), a grid maps naturally onto that bounded range. Each rung is a price the market may revisit multiple times before the event resolves. The strategy assumes the price oscillates; it does not predict which direction wins at resolution.
How does grid trading work on a bounded 0-1 market?
Grid trading divides a chosen price band into equal steps and assigns an order to each step. On a Polymarket outcome priced around $0.45, you might set a grid from $0.35 to $0.55 with several rungs. Buys sit below the current price, sells sit above, and each fill seeds an opposing order at the next level.
A simple illustration:
| Grid level | Order side | Child order type |
|---|---|---|
| $0.55 | Sell / take profit | take_profit_market |
| $0.50 | Sell | limit |
| $0.45 (mid) | Reference price | — |
| $0.40 | Buy | limit |
| $0.35 | Sell / protective stop | stop_market |
The idea is repetition: if the price bounces between $0.40 and $0.50 several times, each round trip banks a small gain. The trade-off is that a grid does poorly when the price breaks decisively out of the band and never returns, which on a binary market can happen as the outcome becomes clearer.
What child order types does a Hey-Traders grid use?
A Hey-Traders grid submits its rungs as three child order types: limit, stop_market, and take_profit_market. For the trigger-based children (stop_market and take_profit_market), the level price is the trigger itself, and there is no separate limit leg attached to those trigger children.
- limit – passive rungs that rest in the book at a set price and fill when the market trades to them.
- stop_market – fires a market order once price crosses the level; used here as a protective stop that exits on a break below the band (it can also be a stop-entry on a break above).
- take_profit_market – fires a market order once price reaches a profit target level.
Important: a trigger price is a threshold, not a guaranteed execution price. When a stop_market or take_profit_market child fires, it executes against available liquidity, so the fill can differ from the trigger level, especially in thin books. Trigger children can also use Reduce Only so they only close or reduce an existing position. For the mechanics of each type, see the order types reference.
When is a grid suitable for prediction-market prices?
A grid suits range-bound Polymarket prices — outcomes that chop sideways while the event is still uncertain and no new information is dominating. It is least suitable near resolution, when prices tend to trend hard toward $0 or $1 and stop oscillating. Match the grid to a market that is genuinely undecided.
Good grid conditions on Polymarket include:
- A market well before its resolution date, with time for the price to move back and forth.
- Reasonable order-book liquidity around your chosen band so rungs can fill near their levels.
- A relatively stable range, without a scheduled catalyst about to force a one-way move.
Weaker conditions include markets close to expiry, illiquid outcomes with wide spreads, and situations where a known event (an announcement, a game, a data release) is likely to resolve direction imminently.
What are the risks of grid trading on Polymarket?
The core risk is binary resolution: every Polymarket share settles at exactly $0 or $1 when the event resolves. A grid that keeps buying dips on the losing side accumulates a position that can settle at $0, turning many small gains into one large loss. Grids assume mean reversion, and binary outcomes ultimately do not revert.
Additional risks to weigh:
- Directional break-outs. If the price leaves your band and never returns, unfilled sell rungs leave you holding inventory as the market trends away.
- Trigger slippage. stop_market and take_profit_market children fill at market against live liquidity, not at the trigger price.
- Sports auto-cancel. On Polymarket sports markets, outstanding limit orders auto-cancel at official game start, which can dismantle resting grid rungs unexpectedly.
- Liquidity gaps. Thin books widen spreads and can leave rungs unfilled or filled at poor prices.
Size positions so a $0 settlement on the full grid inventory is survivable. Polymarket’s own documentation is the authority on native behavior — see the Polymarket Help Center.
How do you set up a Polymarket grid with Hey-Traders?
Because Polymarket lacks a native grid, Hey-Traders adds one as an automation layer and manages the child orders on your behalf. You connect Polymarket, choose a market, define the price band and rung count, and Hey-Traders places and maintains the limit, stop_market, and take_profit_market children.
A typical setup flow:
- Connect your Polymarket account in Hey-Traders and open the target market.
- Describe or configure the grid: upper and lower bound, number of levels, and order size per rung.
- Choose child behavior — passive limit rungs, plus stop_market or take_profit_market triggers where wanted.
- Optionally enable Reduce Only on trigger children so they only close existing exposure.
- Review the ladder and let Hey-Traders submit and monitor the orders.
Hey-Traders is a natural-language quant platform, so you can also state the grid in plain English and refine the parameters before it goes live. Explore related automation in Polymarket algorithmic orders, stop loss, take profit, and trailing stop.
Frequently Asked Questions
Does Polymarket have a native grid order?
No. Polymarket natively supports only limit and market (marketable) orders. Grid, stop loss, take profit, trailing stop, OCO, TWAP, and VWAP are not built in; a grid must be added with an automation tool like Hey-Traders.
What order types do Hey-Traders grid rungs use?
Grid children submit as limit, stop_market, or take_profit_market. For the trigger children (stop_market and take_profit_market), the level price is the trigger, and there is no separate limit leg attached.
Is grid trading a good fit for binary prediction markets?
It fits range-bound, undecided markets where price oscillates. It fits poorly near resolution, because binary shares settle at $0 or $1 and tend to trend one way rather than revert.
Is the grid trigger price guaranteed to fill at that level?
No. A trigger price is a threshold, not a guaranteed execution price. stop_market and take_profit_market children fill at market against available liquidity, so the actual fill can differ from the trigger.
What is the biggest risk of a Polymarket grid?
Binary resolution. Shares settle at exactly $0 or $1, so a grid that keeps averaging into the losing outcome can turn many small gains into one large loss. Size the total grid inventory so a $0 settlement is survivable.
Ready to ladder your Polymarket orders automatically? Set up grid trading with Hey-Traders and add algorithmic order types to a venue that does not offer them natively.