> For the complete documentation index, see [llms.txt](https://docs.yellow.pro/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yellow.pro/spot-trading/market-rules.md).

# Market Rules & Limits

Every spot order is checked against the rules of its market **before it's accepted**. An order that breaks any rule is **not created** — the platform blocks it at submission, so it never enters the order book or your Order History. **If you're unable to place an order, one of the rules below is the most likely reason.** This page lists the rules and the current values for each spot market.

## Order Validation Rules

| Rule                   | What it means                                                                                | You can't place the order if…                                                       |
| ---------------------- | -------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------- |
| **Tick size**          | The smallest allowed price increment. Your price must be an exact multiple of it.            | Price is not a multiple of the tick size.                                           |
| **Step size**          | The smallest allowed amount increment. Your amount must be an exact multiple of it.          | Amount is not a multiple of the step size.                                          |
| **Minimum order size** | The smallest amount (in the base asset) you can trade.                                       | Amount is below the minimum.                                                        |
| **Maximum order size** | The largest amount (in the base asset) per order.                                            | Amount is above the maximum.                                                        |
| **Minimum notional**   | The smallest order *value* (price × amount, in USDT).                                        | Order value is below the minimum notional.                                          |
| **Price band**         | A limit order's price must stay within a percentage band around the current reference price. | A limit (or trigger) price is more than **25%** above or below the reference price. |
| **Available balance**  | You must have enough Available balance (not already committed In Orders) to cover the order. | Available balance is insufficient.                                                  |

> Market orders aren't subject to a placement rule for slippage — they execute immediately, with a protective cap on spend. See [Market-order slippage tolerance](#market-order-slippage-tolerance) below.

## Spot Market Specifications

{% hint style="info" %}
Prices and amounts accept up to 8 decimal places, but must still align to the **tick size** (price) and **step size** (amount) below.
{% endhint %}

| Market         | Min order   | Max order         | Step size | Tick size | Min notional |
| -------------- | ----------- | ----------------- | --------- | --------- | ------------ |
| **WBTCUSDT**   | 0.0001 WBTC | 50,000 WBTC       | 0.0001    | 0.01      | 1 USDT       |
| **ETHUSDT**    | 0.001 ETH   | 50,000 ETH        | 0.001     | 0.01      | 1 USDT       |
| **YELLOWUSDT** | 1 YELLOW    | 10,000,000 YELLOW | 1         | 0.0001    | 5 USDT       |

All spot markets currently apply a **±25% price band** on limit and trigger orders — the price must stay within 25% of the current market price, so the allowed range moves with the market.

## Market-order slippage tolerance

A market order executes immediately at the best available prices, so its average fill price can differ from the submission price. A market **buy** keeps your total spend within about **5%** of the expected amount; if the price moves further, the order fills only up to that limit. Market **sells** are unaffected, since they lock the exact amount you're selling.

## Worked Examples

<details>

<summary>Price not aligned to tick size</summary>

You place a limit buy on **ETHUSDT** at **2,000.005**. The tick size is **0.01**, so the price must end at a multiple of 0.01 (e.g. `2,000.00` or `2,000.01`). You won't be able to place it — round your price to the tick size and try again.

</details>

<details>

<summary>Amount below the minimum / not aligned to step size</summary>

You try to sell **0.0005 ETH**. The minimum order size on ETHUSDT is **0.001** and the step size is **0.001**, so `0.0005` is both too small and not a valid increment. Use `0.001`, `0.002`, and so on.

</details>

<details>

<summary>Order value below the minimum notional</summary>

You place a buy on **YELLOWUSDT** for **3 YELLOW** at **0.50 USDT** — an order value of `1.5 USDT`. The minimum notional is **5 USDT**, so the order can't be placed. Increase the amount or price so the total value is at least 5 USDT.

</details>

<details>

<summary>Limit price outside the ±25% price band</summary>

With ETH trading around **3,000 USDT**, you place a limit buy at **2,200**. That's more than **25%** below the reference price (the floor is `3,000 × 0.75 = 2,250`), so it's blocked. Place your limit price within 25% of the current price — between **2,250** and **3,750** in this example.

</details>

## Related Articles

* [How to Place a Spot Trade](/spot-trading/how-to-place-a-spot-trade.md)
* [Order Types](/spot-trading/order-types.md)
* [Managing Orders](/spot-trading/managing-orders.md)