FuturesHUB / Maintenance margin
Perpetual futures
Maintenance margin
Maintenance margin is the floor under the position. You can open with more collateral than this floor. You cannot stay open once the mark says you have less.
A floor, not a target
Initial margin gets the position on the book. Maintenance margin is the smaller requirement that must remain as losses accumulate. The gap between them is the loss you can carry before the engine steps in. A position opened at the minimum initial margin has a thin gap.
The floor is a percent of notional, and the percent depends on the risk tier. Small positions sit in a tier with a low maintenance rate and a high maximum leverage. Larger notionals step into tiers with higher maintenance and lower maximum leverage.
Equity is measured at the mark
The comparison uses equity marked at the mark price, including unrealized profit and funding already posted to the balance. A last-price wick that the mark does not follow does not change the comparison. A mark move that the chart looks quiet about can.
Funding payments reduce the balance when you are the paying side. A position can drift toward maintenance overnight while the mark is flat, because the funding left the account. Include that drip when you estimate how long a high positive rate takes to matter.
The 0.5% sketch on this desk
The practice desk and the tools workbook assume maintenance of 0.5% so the liquidation sketch has a shape you can inspect. A long sketch is entry times (1 minus 1/leverage plus 0.005). A short sketch is entry times (1 plus 1/leverage minus 0.005). Real tiers are often lower than 0.5% for small positions and higher for large ones.
Treat 0.5% as a teaching assumption. Replace it with the tier rate from the venue when you are sizing a live order. The sketch is not the Bitunix, BloFin, MEXC, or any other engine.
On the ticket
- Read the maintenance rate for your notional tier on the venue's risk-limit table.
- Subtract that requirement from the equity you will have after the open fee. The remainder is the loss the position can carry.
- Recompute after any size change. A larger size can change the tier, not only the dollar requirement.
- Use the desk sketch only to see leverage pull the floor closer. Then read the ticket's own liquidation price.
Questions
Why is maintenance lower than initial margin?
The gap gives the position room to move against you before the engine closes it. Opening at the minimum initial margin makes that room small.
Is 0.5% the real maintenance rate?
It is the assumption inside LiquidityFlow's sketch. Your tier rate is on the venue's risk-limit table and can be a different number.