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Ballista places two kinds of order, and both go to Polymarket’s order book. You can buy from any of the three surfaces.
You cannot sell from the Telegram bot. Every order the bot places is a buy — there is no sell action in a market and none on the positions screen. To close a position, use the web terminal or the Chrome extension.

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How orders are sized

One rule covers every order on every surface:
  • Buys are in dollars. You say what you want to spend — $20 of a market.
  • Sells are in shares. You say how much of your position to close — the 34.5 shares you actually hold.
Market or limit, bot or terminal or extension, it is the same rule, and the input is labelled for the side you are on.

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Market orders

A market order takes whatever the book is offering right now. It is submitted as fill-and-kill: whatever can be filled immediately is filled, and any remainder is cancelled rather than left resting. You may get a partial fill.
A market order is not a guarantee of a price. Thin books move, and on a prediction market a large order can walk several cents up the book. If the price matters more than the fill, use a limit order.

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Limit orders

A limit order rests on the book at a price you choose and fills when someone takes it. Ballista submits limit orders as good-till-cancelled: it stays there until it fills or you cancel it. Two things constrain the price:
  • It must be strictly between 0 and 1 — Polymarket prices are probabilities, so 0.62 means 62¢ for a share that pays $1 if the outcome happens. Exactly 0 and exactly 1 are not valid prices.
  • It is placed in whole cents. A price is snapped to the nearest cent before the order is signed, so 0.555 becomes 0.56.
Sizing follows the same rule as everywhere else: you type dollars on a buy and shares on a sell. Polymarket’s order book counts a limit order in shares on both sides, so on a buy your dollar amount is divided by the limit price and the share count is what gets signed. The price is snapped to the cent before that division, so the shares are worked out against the price the order will actually carry. The division then always rounds down, to the hundredth of a share the exchange accepts. You may spend fractionally less than you typed; you will never spend more. Every surface does both of these the same way.
The terminal and the extension show you the converted count live — ≈ 36.36 shares under a 20buyat55¢—andrefuseanamounttoosmalltobuy0.01sharesatthatprice.Thebothasnolivepreview;ittellsyouinthepromptinsteadwhenyourpricemoved,asin"20 buy at 55¢ — and refuse an amount too small to buy 0.01 shares at that price. The bot has no live preview; it tells you in the prompt instead when your price moved, as in "0.005 becomes $0.01”, and asks for the amount at the snapped price.

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Minimums

The Telegram bot floors both a market buy and a limit buy at $1. That floor is the bot’s own: below roughly a dollar, rounding at the exchange collapses the order to zero size and the book rejects it, so the bot stops you before the round trip rather than after it. The terminal and the extension do not enforce the same floor. They refuse an order worth less than a cent, and a buy too small to reach 0.01 shares at your limit price, and leave anything above that to Polymarket. Either way the fix is the same: increase the size.

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Managing what you placed

The extension lists your open orders and your full fill history, and lets you cancel a resting order. The web terminal lists your open orders on the Portfolio page and next to each market, and can cancel them. Its fill history is per market: each market page shows your fills for that market, and there is no combined history view. Either way the data is read back from Polymarket rather than from Ballista’s own records — what you see is what the exchange has. Cancelling is immediate and frees the balance the order was reserving. The Telegram bot has no open-order list and no trade history at all. Use the terminal or the extension to see or cancel something you placed from the bot.
Everything on this page describes an order you place yourself. Copy trading places orders on your behalf with its own sizing and its own tolerance for price movement — see Copy-trade settings.

Presets

Save a size and a price so you can fire the same order in one click.

Limits

Every minimum and cap in one table.