BloFin risk limits: BTC position-tier MMR ladder and max leverage by size

If you only watch the leverage slider, you miss the moment a quiet add walks you into a tighter row.

Rule: larger position size bands raise maintenanceMarginRate and lower maxLeverage on the live position-tiers ladder for each pair and margin mode.

The ladder (live BTC-USDT cross)

Fetched this run from the public position-tiers endpoint for BTC-USDT cross:

• Band maxSize 2500: maintenanceMarginRate 0.003 (0.3%), maxLeverage 150
• Band 2500 to 5000: maintenanceMarginRate 0.0035 (0.35%), maxLeverage 125
• Band 5000 to 10000: maintenanceMarginRate 0.004 (0.4%), maxLeverage 100
• Band 10000 to 50000: maintenanceMarginRate 0.005 (0.5%), maxLeverage 66
• Band 50000 to 200000: maintenanceMarginRate 0.0075 (0.75%), maxLeverage 50
• Band 200000 to 400000: maintenanceMarginRate 0.0125 (1.25%), maxLeverage 40

The same endpoint returns 101 BTC-USDT tiers. Cross and isolated rows matched on the first six bands this run. ETH-USDT cross opens at maxLeverage 150 with maintenanceMarginRate 0.004 through maxSize 9000. SOL-USDT cross opens at maxLeverage 125 with maintenanceMarginRate 0.004 through maxSize 50. DOGE-USDT cross opens at maxLeverage 75 with maintenanceMarginRate 0.0065 through maxSize 1000. XRP-USDT cross opens at maxLeverage 125 with maintenanceMarginRate 0.004 through maxSize 40. Size units are the maxSize and minSize fields returned by the endpoint for that symbol, so compare your position size in the same units the panel shows.

Formula

maintenance_margin = position_value x maintenanceMarginRate max_leverage_allowed = maxLeverage on the band that contains your size If size crosses the next maxSize boundary, both rates update to the next row. There is no hidden third input: the band is the rule.

Worked steps

1. Pick the pair and margin mode you actually trade (BTC-USDT cross in this walkthrough).
2. Read the band that contains your planned size. Size inside the first BTC band keeps maintenanceMarginRate 0.003 and maxLeverage 150.
3. Compute maintenance_margin = position_value x 0.003. Equity has to stay above that floor or the account is in liquidation territory for that mode.
4. If you scale size past 2500 on BTC-USDT, the next row applies: maintenanceMarginRate becomes 0.0035 and maxLeverage drops to 125. Same growth path, tighter maintenance, lower leverage ceiling.
5. Compare the instrument card: BTC-USDT maxLeverage 150 this run only describes the opening band, not every size you might reach.
6. Repeat the read after every size change. The ladder is the rule; the leverage slider alone is not. Write down the band before and after an add so you see the jump.

What changes it

• Pair: BTC, ETH, SOL, DOGE, and XRP ladders differ on both maxSize steps and opening maxLeverage.
• Margin mode: pull cross and isolated separately; this run matched on the early BTC bands, but always re-check the mode you use before a large isolated book.
• Mark and funding: mark 77249.1 USDT and funding 0.00022 per 8h on BloFin BTC on the live mark-price and funding-rate endpoints this run. Funding is a separate cashflow from maintenance margin, yet it still moves equity.
• Time: tiers can be revised by the venue; the endpoint you fetch today is the source of truth for today's bands.

Common mistakes

1. Treating max leverage on the instrument card as free size. Instrument maxLeverage for BTC-USDT is 150 this run, but that only holds inside the first size band.
2. Adding size without re-reading maintenanceMarginRate. A quiet scale-in can move you from 0.3% to 0.5% maintenance without changing the pair.
3. Mixing last price comfort with mark-based risk. Maintenance is about equity versus the maintenance requirement, not a green candle on last.
4. Copying a BTC band onto SOL or DOGE. Opening rates and maxSize steps differ by symbol.

FAQ

Q: Does raising leverage by itself raise maintenanceMarginRate? A: No. The band is keyed to size. Raising leverage inside the same band does not rewrite the maintenanceMarginRate row. Crossing a maxSize boundary does.

Q: Are cross and isolated ladders always identical? A: Early BTC bands matched this run. Do not assume that forever; fetch both modes before a large isolated book.

Q: Where do ETH and SOL differ from BTC? A: Opening maxLeverage and the maxSize steps differ. ETH opens at maintenanceMarginRate 0.004 / maxLeverage 150 through maxSize 9000. SOL opens at maintenanceMarginRate 0.004 / maxLeverage 125 through maxSize 50.

Questions? Drop them below.