Funding

Perpetual funding keeps the order book trading near the index price. Reya recalculates the funding rate every 5 seconds and accrues funding continuously into position PnL.

How the funding rate is computed

premium   = (reference − index) / index
rate_8h   = premium + clamp( interestRate_8h − premium, ±interestClamp )
dailyRate = clamp( rate_8h × 3, ±dailyRateCap )

• reference — the composite impact price when available, or the Stork CEX-mark feed when the composite impact price is unavailable because the book is too thin or EMA-VWAP has not yet been primed by a trade.

• premium — how far the book trades from the index, as a fraction of the index.

• interestRate_8h — a fixed per-8h interest term. When the premium is small the interest term dominates; when the premium is large the clamp absorbs the interest term.

• dailyRate — the on-chain convention is a daily rate (rate_8h × 3), bounded by dailyRateCap.

Sign: dailyRate > 0 ⇒ longs pay shorts; dailyRate < 0 ⇒ shorts pay longs.

The rate is recomputed from the current book and index every 5 seconds, with no time-weighted averaging.

Worked-example parameters

Parameter	Value
interestRate_8h	0.01% (0.0001)
interestClamp	±0.05% (0.0005)
dailyRateCap	96% / day (0.96) — a safety bound, rarely binding
Recompute interval	5 s

These values illustrate the calculation below; they are not a live parameter feed or defaults for every market. API 3.6.2 does not expose the configured interest term, clamp or daily cap. Read the current fundingRate from GET /v2/perpMarket/{symbol}/summary or the market-summary WebSocket channel; see public configuration and live values. Use the reported rate for your integration rather than recomputing it from this example. The API rate's hourly percentage units are explained below.

How funding is charged

Funding uses a capped daily rate and accrues per side as:

fundingValueDelta = dailyRate × markPrice × elapsedDays × baseMultiplier

Your position's share is folded into its realised PnL on every position update — there is no separate funding transfer to track. Note that funding accrues against the mark price, not the index.

Funding freshness and outages

Reya checks funding-rate freshness before allowing new trades.

Stale funding pauses new trading — not your positions. Each market has a staleness window (a small multiple of the 5 s push cadence). If no fresh funding rate arrives within that window, opening or changing a position is temporarily rejected until a new rate is pushed. Liquidations and auto-deleveraging keep working throughout, and viewing margin, adding collateral, and withdrawing are unaffected.

An outage is never charged retroactively. Funding accrues on-chain from the timestamp of the last pushed rate, so a gap in pushes does not silently accumulate. When pushes resume, the market charges at most one staleness window of funding — a short, bounded amount — at the newly-pushed rate, and forgives the rest of the gap. There is no backfill or catch-up charge for the missed period. This is a fixed, pre-committed policy: the on-chain outcome is final and is not reconciled or adjusted off-chain afterwards.

Worked example

ETH index = $3,000, book reference (impact) price = $3,030 — the book is trading 1% rich:

• premium = ($3,030 − $3,000) / $3,000 = +1.00%

• interestRate_8h − premium = 0.01% − 1.00% = −0.99%, clamped to ±0.05% → −0.05%

• rate_8h = 1.00% + (−0.05%) = 0.95%

• dailyRate = 0.95% × 3 = 2.85% / day (well inside the 96%/day cap)

Because dailyRate > 0, longs pay shorts. Holding a 10 ETH long (~$30,000 notional) for one hour at this rate accrues ≈ $30,000 × 2.85% ÷ 24 ≈ $35.6 paid (illustrative — the rate is recomputed every 5 s, so it varies over the hour).

What the API reports

Funding-rate history is not yet available for integration. See Under Development.

The mechanism above works in a daily rate, but the off-chain API normalises what it returns. The fundingRate value in market data is an hourly rate, already expressed as a percentage — the service takes the on-chain daily rate, divides by 24, and multiplies by 100 (fundingRate = dailyRate ÷ 24 × 100). So the 2.85% / day from the worked example above surfaces as a fundingRate of ≈ 0.119 (i.e. ≈ 0.119% per hour); multiply by 24 to recover the daily percentage used in the accrual formula.