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The Markets tab is the extension’s own market browser: search, pick an outcome, place an order. It is what you use when you are not already on a Polymarket page — when you are, the on-page panel is quicker. Type into the search box at the top. Results appear as you stop typing, and only cover markets that are currently active and open. Each result shows the event image and title, plus either the YES and NO prices — for events with a single market — or a count like 12 markets. Pressing a result takes you straight to the order form if the event has one market, or to a list of its markets if it has several. In that list, every market shows its YES and NO prices; anything resolved or not accepting orders is greyed out and cannot be opened.

Place an order

The order form is the same shape every time.
1

Check YES or NO

Both buttons show the current price in cents, and YES is already selected when the form opens. Press NO if that is the side you want — nothing points out that the default was left in place.
2

Apply a preset (optional)

If you have any presets, an Apply a preset… dropdown sits above the form. Choosing one fills in the order type, side, price and size in one go. You can still edit anything afterwards.
3

Choose Limit or Market, and Buy or Sell

Two toggles side by side.
4

Enter price and size

Limit orders take a price between 1¢ and 99¢, entered as a decimal — 0.35 is 35¢. The size field asks for dollars on a buy and shares on a sell; the label tells you which.
5

Press Buy or Sell

The order goes to Polymarket’s order book. A limit order rests there until it fills or you cancel it from the History tab.
If the market is not currently accepting orders, the form says so and the button stays disabled.

Buys in dollars, sells in shares

One rule covers every order across Ballista: you buy with an amount of money, and you sell a number of shares. You buy $20 of an outcome; you close the 34.5 shares you actually hold. A limit buy is the one case where the two units meet, and the form does the conversion for you: enter $20 at 0.35 and a line under the fields reads ≈ 57.14 shares @ 35¢. That is the order that gets placed, and the share count is always rounded down to the nearest 0.01, so the cost never exceeds the amount you typed. Limit sells get the same treatment in one direction only — a share count is floored to 0.01, and the line shows the floored figure, so what you read is what is placed.

Prices sit on the 1¢ tick

Polymarket’s book works in whole cents, so your limit price is snapped to the nearest cent before anything else happens — before the share conversion, and before the order is signed. When a typed price is moved, the same line tells you: ≈ 57.14 shares @ 9¢ — price snapped from 0.086. Because the snap comes first, the price in that line is the price your order is placed at, and the share count is the count it buys at that price. The three numbers cannot disagree. A price outside the tradable band is refused outright with Price must be between 1¢ and 99¢, and the order button stays disabled. Two other messages appear in the same place when an order cannot be placed as typed:
  • Amount too small to buy 0.01 shares @ 35¢ — your dollar amount does not reach one share-cent at that price.
  • Order must be worth at least $0.01 @ 35¢ — the order clears a share-cent but is worth too little for the book.

Save the setup as a preset

Next to the order button is Save preset. Press it, then Confirm save, and the current order type, side, price and size become a reusable preset — available in the on-page panel, in this dropdown, and in the Presets tab. The preset stores the size in the unit you entered it in — dollars for a buy, shares for a sell — and, for a limit preset, the snapped price. A limit preset cannot be saved without a valid price, so Confirm save stays disabled until the price is one the book accepts. Presets are not tied to the market you saved them from. They are a shape of order, so a BUY market $25 preset can be fired at anything. You can hold six presets per combination of order type and side — six limit buys, six market buys, and so on. Past that, saving fails and the popup shows the message maximum of 6 presets per order type, side, and platform. Delete one from the Presets tab to make room.