Maintenance margin tiers: apply the rate and deduction

Translate a progressive schedule into two equivalent forms

Use an invented schedule for positive marked notional N up to 20,000 USDT. The first 10,000 requires 1%; the portion above 10,000 through 20,000 requires 2%. Exactly 10,000 belongs to the first tier. There are no open orders or estimated closing-fee reserves in this model.

For 10,000 < N ≤ 20,000, calculate 10,000 × 0.01 + (N − 10,000) × 0.02. Expanding gives 0.02N − 100. The 100 deduction preserves the first slice's lower rate; it is not an optional discount or additional collateral.

Revalue notional even when quantity is unchanged

Hold quantity at 100 units while the mark moves from 99 to 101 USDT per unit. Notional moves from 9,900 to 10,100 without another trade. Under this schedule, maintenance rises from 99 to 102. A tier transition can therefore occur through valuation alone.

This does not establish that the account became less safe. Position P&L, collateral value and other requirements may also change. Real venues have product-specific notional definitions, order reserves, fee treatment and rounding. The example's output is one component, not a complete liquidation threshold.

Check the boundary before trusting the shortcut

At notional 10,000, requirement is 100. At 10,100, it is 100 plus 2 on the additional 100, giving 102. Applying 2% to everything would give 202, an overstatement of 100.

At 15,000, the first slice requires 100 and the extra 5,000 requires another 100. The shortcut agrees: 15,000 × 0.02 − 100 = 200. An independent slice calculation is a useful review of a rate-and-deduction table.

A venue label does not specify a universal formula

Do not copy a position-maintenance formula into an order requirement or assume another venue uses the same boundaries. Record product, account mode, effective rule version and omitted costs before using real settings. Our invented 1% and 2% rates are not current symbol parameters.