Perpetuals

Pod supports perpetual futures as a native market type. Perpetual contracts track the price of an underlying asset without expiry, using a funding rate mechanism to keep the contract price aligned with the spot price.

Positions are collateralized under a single cross-margin account shared with spot markets - see Margin for margin requirements, liquidation, and ADL.

Mark price

Each perp market maintains a mark price - a smoothed reference price derived from the order book and the oracle. Mark price is the reference used for margin, liquidation, take-profit/stop-loss, and everything else related to leverage and PnL.

It is recomputed every batch:

price_diff_ema = clamp(ema(clearing_or_mid − oracle_price, 3 min), 0, max_premium)
mark_price     = clamp(oracle_price + price_diff_ema, last_mark_price, mark_clamp_pct × last_mark_price)

• clamp(x, center, half_width) - clips x to [center − half_width, center + half_width].

• clearing_or_mid - the batch's uniform clearing price if it matched, otherwise the order book mid price.

• ema(·, 3 min) - a 3-minute exponential moving average of the gap between the book price and the oracle.

• max_premium - a per-market bound; price_diff_ema is clamped to ±max_premium so mark cannot drift arbitrarily far from the oracle.

• mark_clamp_pct - a per-market bound limiting how far mark_price can move from the previous batch's mark price in a single batch, expressed as a fraction of last_mark_price.

Funding

Perpetuals use a funding mechanism to keep the mark price aligned with the underlying oracle price. The funding rate is recomputed and applied every batch - each open position pays or receives its share directly into cash, with no per-period lump payment.

Funding rate

For each market, on every batch:

funding_rate = clamp(
    interest_rate
      + saturate((impact_bid − oracle_price) / oracle_price)
      − saturate((oracle_price − impact_ask) / oracle_price),
    0,
    max_funding_rate,
)

• oracle_price - the spot price reported by the oracle for the underlying.

• impact_bid / impact_ask - the effective price a taker would get when opening a short / long position of size impact_notional (a per-market USD amount, defaulting to $10,000) against the current batch auction.

• saturate(x) - max(x, 0): each term contributes only when it pushes the perp away from spot.

• interest_rate - a per-market constant, defaulting to 0.01% per 8 hours.

• max_funding_rate - a per-market cap on the rate's magnitude, defaulting to 4% per hour.

• funding_rate is signed: positive means longs pay shorts, negative means shorts pay longs.

When the perp trades at a premium (impact_bid above the oracle) the first saturate term is positive and longs pay; when it trades at a discount (impact_ask below the oracle) the second term dominates and shorts pay. The rate is computed and applied per batch - interest_rate and max_funding_rate are shown normalized to 8-hour and hourly figures only for readability.

Per-position payment

Every batch, each open position settles funding into cash:

funding_payment = funding_rate × oracle_price × position.size
realized_pnl   −= funding_payment

position.size is signed (long positive, short negative), so a positive funding_rate charges longs and credits shorts, and vice versa. After settlement, the position's unrealized PnL is pure price drift: (mark − entry) × size.