📄Perpetual Trading Specifications

Equations

Margin

BBOX utilizes a cross-margin model and the concept of Health to evaluate account values.

• Health(weight) = Weighted Collateral value + $\sum{((Si × Pi × Weight)- Si × Pentry))}$

  or Weighted Collateral value + $\sum{((Si × Pi × (Weight-1)) + Pnl))}$

  or = Weighted Account Value - margin requirements(weight)

• Collateral value = $\sum{(Si × Pi × Weight)}$
• Initial Health = Health(initial weight) ~= Free Collateral to open position

  • If Initial Health < 0, accounts cannot open new positions.

  • Initial weight = 1-initial margin ratio if long, initial margin ratio if short

• Maintenance Health = Health(maintenance weight) ~= Free Collateral until liquidation

  • If Maintenance Health < 0, accounts can be liquidated.

  • Maintenance weight = 1-maintenance margin ratio if long, maintenance margin ratio-1 if short

• Account Value = Assets + Unsettled Pnl

Funding Payment

BBOX uses an efficient block-based funding payment mechanism which settles when there are market actions instead of hourly or every 8 hours. The funding rate shown in UI is the hourly rate of the current block for readability.

Fees

• trading fee = 0.1%

• 80% earned by LPs and 20% goes to insurance fund to support system health.

Leverage

• max account leverage: $\frac{1}{Initial Margin Ratio}$ = 10x currently.

Liquidation discount

• liquidator discount (reflected in liquidation price)

  • Long: $\frac{oracle\_price * (maintenance\_asset\_weight + 1)} {2}$
  • Short: $\frac{oracle\_price * (maintenance\_liability\_weight + 1)} {2}$
  • With a 0.9 and 1.1 weight, this means a 5% discount from the oracle price