For the complete documentation index, see llms.txt. This page is also available as Markdown.

Contract Specifications

Perpetual contract specifications — tick size, step size, minimum order size and value, price band, max leverage, and maintenance margin — and why an order might not be accepted.

Every perpetual order is checked against the contract's rules 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 perpetual contract.

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 price must stay within a range around the reference (mark) price.

Price is below 50% or above 150% of the reference price.

Maximum leverage

The highest leverage allowed on the contract.

Selected leverage exceeds the maximum.

Available margin

You must have enough free margin to open or increase the position.

Available margin is insufficient.

The price band is why a limit order placed far from the current price can be blocked even when its price is otherwise valid. It prevents fat-finger orders and trades at unrealistic prices.

Contract Specifications

Contract
Min order
Max order
Step size
Tick size
Price band
Min notional
Max leverage
Maintenance margin

BTCUSDT-PERP

0.001 BTC

1,000,000 BTC

0.001

0.1

50% – 150% of reference

1 USDT

100×

0.5%

ETHUSDT-PERP

0.001 ETH

1,000,000 ETH

0.001

0.01

50% – 150% of reference

1 USDT

100×

0.5%

The maintenance margin rate (MMR) is the fraction of position notional you must keep to avoid liquidation. See Margin & Leverage and Liquidation & Mark Price for how leverage and maintenance margin affect your positions.

Market-order slippage tolerance

A market order opens immediately at the best available price, so the fill price can differ from the mark price shown at submission. To stay funded if it fills at a worse price, a market order reserves about 5% extra initial margin on top of the normal requirement.

Worked Examples

Price not aligned to tick size

You place a limit order on BTCUSDT-PERP at 60,000.05. The tick size is 0.1, so the price must end at a multiple of 0.1 (e.g. 60,000.0 or 60,000.1). You won't be able to place it — round your price to the tick size and try again.

Limit price outside the price band

With BTC trading around 60,000, you place a limit buy at 20,000 — below 50% of the reference price (30,000). The order falls outside the price band, so it's blocked. Place the order within the allowed range around the current price.

Amount below the minimum / not aligned to step size

You try to open a 0.0005 BTC position on BTCUSDT-PERP. The minimum order size 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.

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