Before you trade MEXC perps: BTC BY_VOLUME risk limit ladder (mmr, imr, maxLeverage)

Rule: riskLimitType for BTC_USDT is BY_VOLUME. As your position volume climbs through riskLimitCustom levels, maintenance margin rate and initial margin rate rise while maxLeverage falls.

Live BTC_USDT ladder (this run)

From the public contract detail endpoint for symbol BTC_USDT:

• Level 1: maxVol 120000, mmr 0.001 (0.1%), imr 0.002 (0.2%), maxLeverage 500
• Level 2: maxVol 310000, mmr 0.004 (0.4%), imr 0.005 (0.5%), maxLeverage 200
• Level 3: maxVol 480000, mmr 0.005 (0.5%), imr 0.01 (1%), maxLeverage 100
• Level 4: maxVol 2800000, mmr 0.01 (1%), imr 0.02 (2%), maxLeverage 50
• Level 5: maxVol 17500000, mmr 0.02 (2%), imr 0.05 (5%), maxLeverage 20
• Level 6: maxVol 19000000, mmr 0.05 (5%), imr 0.1 (10%), maxLeverage 10

Contract-level maxLeverage on that detail payload is 500, which matches Level 1 only. Past Level 1, the level's own maxLeverage is the ceiling that matters.

Formula

maintenance_margin = position_volume x mmr initial_margin_requirement = position_volume x imr Allowed leverage for that size is the maxLeverage on the active level, not the contract headline alone.

Worked steps

1. Read the BTC_USDT riskLimitCustom array (or the on-screen risk limit table) before sizing.
2. Find the lowest level whose maxVol still covers your planned volume V.
3. Apply that row: mmr, imr, maxLeverage.
4. Level 1 path: if V stays at or under 120000, mmr is 0.001 and maxLeverage is 500. maintenance_margin = V x 0.001.
5. If V moves above 120000 into Level 2, mmr becomes 0.004 and maxLeverage drops to 200. maintenance_margin = V x 0.004. Same coin, tighter floor, lower leverage ceiling.
6. Compare Level 1 versus Level 2 on the same V variable only after you know which level owns V. Never multiply a Level 1 mmr by a Level 2 volume.
7. Repeat after every add or hedge that changes net volume. BY_VOLUME means the ladder keys off volume, not off the leverage slider by itself.
8. Keep regional fees out of this worksheet. They change cost, not mmr.

What changes it

• Volume: crossing maxVol is what advances the level.
• Pair: this package quotes BTC_USDT. ETH and SOL have their own riskLimitCustom arrays; do not copy BTC rows onto them.
• Region: futures fee rates vary by region on MEXC. That does not rewrite mmr, but it does change round-trip cost, so keep fee checks local to your account view.
• Liquidation path: the Liquidation and Risk Limit help material sits beside this ladder; mark-based equity still drives when liquidation handling starts.
• Account requirements: follow the live account verification rules shown for your region. This guide does not classify MEXC account tiers beyond that.

Common mistakes

1. Reading maxLeverage 500 on the contract and sizing as if Level 1 lasts forever.
2. Assuming mmr stays at 0.1% after you scale through Level 2+.
3. Mixing fee-tier talk into risk-limit math. Fees vary by region; riskLimitCustom is the volume ladder.
4. Copying BTC mmr onto ETH or SOL without fetching those symbols.

FAQ

Q: Do account verification rules belong in the risk ladder? A: Follow whatever the live account page shows for your region. The riskLimitCustom rows above are about volume, mmr, imr, and maxLeverage only.

Q: Do ETH and SOL share the BTC ladder? A: No. Fetch each symbol's riskLimitCustom. This walkthrough is BTC_USDT only.

Q: Does lowering leverage move me to a friendlier mmr? A: Not by itself. Volume decides the level. Cutting leverage without cutting volume leaves you on the same mmr row.

Q: What is the fastest sanity check before a large BTC add? A: Read your current level's maxVol and the next level's mmr. If the add crosses maxVol, price the new maintenance_margin = V x next_mmr before you click.

Curious how others plan to approach this.