Bitbase hedge mode: April 20 Mark Price IM/MM update plus Step 2 netting

Two official pieces matter together: the April 20, 2026 margin calculation update that introduces Mark Price into IM and MM under hedge mode, and Step 2 of the contract liquidation mechanism where hedged size is netted before partial liquidation. Miss either piece and the mode looks like free insurance when it is not.

Rule: liquidation uses Mark Price, not Last Traded Price. MMR = Maintenance Margin Requirement / Effective Margin Equity x 100%. When MMR reaches 100%, liquidation handling starts. In Hedge Mode, Step 2 nets offsetting long and short size on the same contract before later steps.

April 20 Mark Price changes (Hedge Mode)

Effective April 20, 2026 23:00 UTC, Bitbase updated perpetual margin math:

• Cross Margin: Initial Margin uses Mark Price instead of Entry Price.
• Isolated Margin: Maintenance Margin switches to Mark Price; Initial Margin stays on Entry Price.
• Liquidation price math was adjusted with the update.

Isolated Hedge Mode position value moves from Position Quantity x Entry Price to Position Quantity x Mark Price. Isolated Hedge Mode Position MM moves from an Entry Price x MM Rate path to a Mark Price x MM Rate path (fee terms in the help center still reference Entry Price in the published formula lines). Cross Hedge Mode also shifts position value onto Mark Price and recalculates IM on the new Mark Price path described in that update.

Formulas

MMR = Maintenance Margin Requirement / Effective Margin Equity x 100% Liquidation handling starts at MMR = 100%. Position Value (post-update, hedge paths above) = Position Quantity x Mark Price Isolated Hedge MM (post-update core) uses Mark Price x MM Rate in the maintenance term. Always read the live help center for the full fee add-on terms; this guide does not invent fee rates.

Worked steps

1. Confirm you are in Hedge Mode on the pair ($BTC.USDT, $ETH.USDT, $SOL.USDT, $XRP.USDT, or $DOGE.USDT perps as listed on the platform).
2. Note Cross versus Isolated. That choice picks which April 20 line applies (Cross IM on mark versus Isolated MM on mark).
3. Read Mark Price on the position, not only Last on the chart. Liquidation risk follows Mark Price.
4. If you hold both long and short on the same contract, understand Step 2: the engine nets the offsetting size first, which reduces overall position size and the maintenance requirement, then recalculates risk. If risk clears, later steps stop.
5. If netting is not enough, Step 3 can attempt partial liquidation for positions in risk-limit tier 2 or above, targeting a return to tier 1 size. Step 4 is insurance-fund take-over of any remainder at the bankruptcy price path the help center describes.
6. Re-check MMR after every hedge add. Adding a hedge that does not actually offset the same contract does not get you Step 2 netting.
7. On Cross Mode after April 20, remember the impact table: on a long during an uptrend, Initial Margin can rise with Mark Price and lock more unrealized PnL, which can cut what remains free to open new size.

What changes it

• Margin mode: Cross versus Isolated changes which side of the April 20 update hits IM versus MM.
• Hedge flatness: only true opposite size on the same contract nets in Step 2.
• Mark versus last: a last-price bounce can disagree with Mark Price; a position can enter liquidation even when Last has not reached the estimated liquidation price on the position page.
• Risk-limit tier: Step 3 partial liquidation behavior depends on being in tier 2 or above.
• Fees: fee add-ons in the published MM lines still matter; pull the live rates rather than inventing them here.

Common mistakes

1. Chart-watching Last while MMR is computed against Mark Price.
2. Assuming any short against any long nets. Step 2 is same-contract hedge mode netting.
3. Ignoring April 20: Cross IM now tracks Mark Price, so up-moves can lock more unrealized PnL into IM on longs under the published impact table.
4. Treating hedge mode as a substitute for size discipline. Netting helps only when size truly offsets.

FAQ

Q: Does this package quote Bitbase identity-check withdrawal limits? A: No. Those figures are out of scope.

Q: Does this package call Bitbase a skip-verification venue? A: No. Follow the live account flow the platform shows.

Q: What is the one liquidation line to remember? A: Mark Price drives the check, MMR at 100% starts handling, and Hedge Mode nets offsets at Step 2 before partial liquidation and take-over.

Q: Where do risk-limit tiers still matter in hedge mode? A: Step 3 partial liquidation refers to tier 2 or above. Netting is Step 2; tiers still shape what happens if netting is not enough.

Worth watching how it trades over the next few sessions.