> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aura.markets/llms.txt
> Use this file to discover all available pages before exploring further.

# Trading on Aura

> Aura uses a central limit order book. Place market or limit orders, build parlays, and earn from spreads.

Aura uses a **central limit order book (CLOB)**. Prices are shown as
probabilities (0–100%), and liquidity comes from limit orders posted by
traders and market makers. When you place a market order, it fills
instantly against the best available orders on the book. When you place a
limit order, you choose your price and your order sits on the book until
someone matches it (or you cancel it).

## Buying outcome shares

<Steps>
  <Step title="Navigate to your desired market">
    Select the market you wish to trade from the Aura homepage or search
    results.
  </Step>

  <Step title="Choose outcome">
    Pick an outcome — typically **YES** or **NO**.
  </Step>

  <Step title="Choose order type">
    <Tabs>
      <Tab title="Market order (instant fill)">
        Enter how much USDT (collateral) you want to spend (or the share
        quantity you want). The order fills immediately against the best
        available asks on the order book. Your final average price depends
        on available depth.
      </Tab>

      <Tab title="Limit order (set your price)">
        Enter a price (probability % / 0–100) and a quantity (shares). Your
        order is posted to the order book and only fills if another trader
        matches it. You can cancel open orders anytime before they fill.
      </Tab>
    </Tabs>
  </Step>

  <Step title="Confirm transaction">
    Click **Buy** and confirm via your connected wallet (or passkey flow).
  </Step>
</Steps>

## Selling outcome shares

<Steps>
  <Step title="Switch to Sell tab">
    On the market page, select the **Sell** tab.
  </Step>

  <Step title="Select outcome shares">
    Choose which shares you want to sell (YES or NO).
  </Step>

  <Step title="Choose order type">
    <Tabs>
      <Tab title="Market sell (instant fill)">
        Sells immediately into the best available bids on the book. Your
        average fill price depends on book depth.
      </Tab>

      <Tab title="Limit sell (set your price)">
        Set a price and quantity to sell. The order sits on the book until
        a buyer matches it. You can cancel open orders anytime if you
        change your mind.
      </Tab>
    </Tabs>
  </Step>

  <Step title="Confirm transaction">
    Click **Sell** and confirm via your connected wallet (or passkey flow).
  </Step>
</Steps>

## Parlay bets (multi-leg trades)

* **Multiple legs** — select 2 to 5 different market outcome positions
  (legs) to include in one parlay bet.
* **Combined odds** — the odds of each leg multiply together, yielding a
  combined payout that can reach **up to 50× the original stake** if all
  legs are correct.
* **All-or-nothing payout** — every leg must win for the parlay to pay
  out. If any leg fails, the parlay is lost and no payout is given.
* **Dynamic odds** — parlay odds reflect the live order book at the time
  you place the bet. As legs are added, the overall odds shift based on
  available liquidity and prices.

## Understanding fees

A **2.5% trading fee** is charged in USDT on executed volume. The fee
splits between the market creator and the protocol treasury:

| Slice             | Recipient                                                                                              |
| ----------------- | ------------------------------------------------------------------------------------------------------ |
| **Creator share** | A tier-scaled cut (1–30%) goes to the market creator.                                                  |
| **Treasury**      | The remainder funds liquidity rewards, dispute incentives, referral payouts, and protocol development. |

Two additional rewards flow from the treasury's share:

* **Referrals** — when a trader uses a referral link, the referrer earns
  **10% of the treasury share** of that trader's fees.
* **Dispute resolution** — voters who decide disputed markets are
  rewarded through a separate slashing mechanism. See
  [Resolution & Disputes](/markets/resolution-and-disputes).

<Tip>
  No other fees exist — no exit tax, hidden spread, or performance fee.
</Tip>

### Spreads & slippage

* **Spread** — the gap between the best bid and best ask on the book.
* **Slippage** — when a trade consumes multiple price levels due to
  limited depth.

## Potential returns

| Market resolves YES            | Market resolves NO              |
| ------------------------------ | ------------------------------- |
| Each YES share pays **1 USDT** | Each NO share pays **1 USDT**   |
| All NO shares expire worthless | All YES shares expire worthless |

Once a market outcome is finalized, winning shares are settled and paid
out in USDT to the wallet that holds them. Payouts are processed
automatically as part of settlement.

## Collateral & settlement safety

Buy orders lock USDT collateral based on the order's price and size. If
an order is partially filled or canceled, **any unused locked USDT is
refunded** immediately.

## TL;DR

* Central limit order book — bids and asks form 0–100% probabilities.
* Market orders cross the book; limit orders provide liquidity.
* 2.5% USDT fee on executed volume, split between creator and treasury.
* 1 USDT per winning share at settlement.
* Up to 50× payout on 2–5-leg parlays.