Fees, funding and the borrow fee

A position pays a trading fee when it opens and when it closes, a flat keeper fee for each fill, funding while it holds the side the skew leans to, and a borrow fee that rises as the market fills its caps. The protocol's fees are split between the vault, the protocol, the insurance fund and the market's proposer; the protocol's share buys ANYPERP and burns it.

What a position pays

The skew impact in the fill price is part of the price, not a separate charge (Trading).

Trading fee

The trading fee is 10 bps of the notional at the fill price, rounded up to the next USDC base unit. It is charged on opens, on additions (on the added size only) and on closes. At an open it comes out of the escrowed margin; at a close it comes out of the payout.

For example, a $12,000 long pays $12.00 to open. If the index rises 10% and the position closes at $13,200 of notional, it pays $13.20 to close.

Keeper fee

Keepers are permissionless bots that execute orders, liquidations and settlements on chain. Each of those actions pays the keeper that sent it a flat keeper fee in USDC, set in protocol configuration. The ticket's Margin row includes it. Like the trading fee, it comes out of the margin at an open and out of the payout at a close.

Liquidation fee

A liquidation pays 1% of the position's notional at the index, from the equity left after the keeper fee. For example, a position liquidated at $8,888.89 of notional pays $88.89. Whatever equity remains after both fees goes to the owner's claim balance.

Funding

Funding is the balancing price of a market. There is no spot market for a listener count, so funding does not anchor to one; it moves with the vault's exposure and pays whichever side reduces it.

Skew

The skew is long open interest minus short open interest, in USDC at the index:

$$s = N_{long} - N_{short}$$

The vault holds the other side of $s$: when longs outweigh shorts, the vault is short the difference.

The rate and its velocity

The funding rate $f$ is a rate per hour. It doesn't jump to a level set by the skew; it drifts, at a speed proportional to the skew. Over $\Delta$ hours:

$$f_{t+\Delta} = f_t + \dot f \cdot \frac{s}{S} \cdot \Delta$$

$\dot f$ is the market's funding velocity and $S$ its skew scale, both set at listing. While longs outweigh shorts the rate climbs; while shorts outweigh longs it falls; with no skew it holds its level. A positive rate means longs pay and shorts receive; a negative rate means shorts pay and longs receive. The markets table shows which side pays, or "level" when neither does.

What a position pays

At every print the market adds the period's funding to a cumulative funding index $F$, using the average of the rate at the start and end of the period:

$$\Delta F = I_t \cdot \frac{f_t + f_{t+\Delta}}{2} \cdot \Delta$$

A long of $q$ contracts pays $q \cdot \Delta F$ and a short receives it (the reverse when $\Delta F$ is negative). Each position records $F$ when it opens, and the difference settles when it closes.

For example, take a market with $S$ = $5,000,000 and $\dot f$ = 0.0001 per hour², a skew of +$500,000 ($s/S$ = 0.1) held for a day, and a rate starting at zero. The rate climbs by 0.001%/h every hour and reaches 0.024%/h after 24 hours. The average over the day is 0.012%/h, so a $10,000 long pays $28.80 for the day and a $10,000 short receives $28.80.

Funding and the vault

Longs pay on the long open interest and shorts receive on the short open interest, so the difference, $(N_{long} - N_{short}) \cdot \Delta F / I_t$, belongs to the vault. As the rate drifts toward the side that adds to the skew, that side pays the vault for the exposure it leaves there.

Borrow fee

Every open position pays a borrow fee, long or short. Its hourly rate rises with how full the market's caps are, measured on the fuller side:

$$b = b_0 + b_1 \cdot \max\left(\frac{N_{long}}{\text{cap}_{long}}, \frac{N_{short}}{\text{cap}_{short}}\right)$$

$b_0$ is the market's base rate and $b_1$ its slope, both set at listing. A position pays $b$ on its notional for each hour it is open, accrued at every print through a cumulative borrow index, like funding. The market page shows the current rate under Borrow.

For example, with $b_0$ = 0.0005%/h and $b_1$ = 0.004%/h, a market whose long side is at 75% of its cap and short side at 20% charges 0.0005% + 0.75 × 0.004% = 0.0035%/h. A $10,000 position open for a day pays $8.40.

The borrow fee is collected when the position closes, is liquidated or settles, and it is split like the other fees.

How charges show up

Each position shows "Funding · borrow": what it has accrued so far. Both are part of its equity, its liquidation price and its payout. Nothing is taken from your wallet while a position is open; the charges settle against the position's margin and PnL at the close.

Where fees go

Every trading fee, liquidation fee and borrow fee is split four ways:

For example, the $12.00 fee on a $12,000 open splits into $7.20 for the vault, $2.40 for the protocol, $1.20 for the insurance fund and $1.20 for the proposer. The protocol, insurance and proposer shares round down to the base unit, and any remainder stays with the vault. Funding is not split: it moves between traders and the vault. The keeper fee goes to the keeper in full.

The Vault page shows the vault's earned fees, in total and over the last 24 h, and the insurance fund's balance.