Fees

All Fees at a Glance

Fee Schedule

Both conditions must be met for maker. If either fails, you pay taker.

Fee Calculation

The fee is a percentage of your position's notional size (collateral x leverage), not your collateral alone.

Open Interest Skew

The protocol tracks open interest (OI) per side on each pair. When one side is larger, a skew exists. Your classification as maker or taker depends on whether your order reduces or increases that skew.

Example: BTCDOM has $5M long OI and $3M short OI. A new short reduces the imbalance, so it qualifies as a maker order (assuming leverage is 20x or below). A new long increases the imbalance and pays taker regardless of leverage.

Fee Distribution

Half of every fee flows to the USDC vault, increasing share value for liquidity providers. The other half accrues to the protocol treasury.

Price Impact

Every trade receives a small spread adjustment based on the current OI skew. This is not a fee — it adjusts your execution price slightly worse than the oracle price.

$$spread = 0.001\% \times (1 + |skew|)$$

Where skew = (longOI - shortOI) / totalOI, ranging from -1 to +1.

At balanced OI (skew = 0), spread is 0.001%. At maximum skew, spread doubles to 0.002%. The adjustment is added to the price for longs and subtracted for shorts.

Practical impact: On a $10,000 position with balanced OI, price impact moves your entry by ~$0.10. At max skew, ~$0.20. Negligible for most trades, but worth knowing it exists.

Oracle Fee

Each trade action that requires a price lookup (opening, closing, updating TP/SL, removing collateral) charges a small ETH fee to cover oracle infrastructure costs. This is separate from USDC trading fees.

Your wallet needs a small ETH balance on Base to cover these fees. Adding collateral is the only position action that doesn't require an oracle fee (it executes synchronously without a price lookup).

Funding Rate

Funding is a continuous per-block payment between longs and shorts. The side with more open interest pays the side with less. The rate scales with the size of the imbalance — bigger skew means higher funding.

How the Rate is Set

The protocol computes a target funding rate from the current OI imbalance using a hill function, then smooths the actual rate toward that target over time.

Step 1 — Normalize the OI skew. The protocol computes the difference between long and short OI as a fraction of the larger side, producing a value between -1 (fully short-skewed) and +1 (fully long-skewed):

$$oiDelta = \frac{oiLong - oiShort}{\max(oiLong,\ oiShort,\ oiCap)}$$

Step 2 — Apply the hill function. The normalized delta maps to a target rate through a saturating curve that is near zero at balanced OI, accelerates through moderate skew, and flattens near maximum skew:

$$x = 1.84 \times oiDelta$$ $$hill = \frac{x^2}{0.16 + x^2}$$

The hill function output ranges from 0 (balanced) to ~0.95 (full skew). The constants 1.84 (stretch) and 0.16 (saturation) are hardcoded and control the curve's steepness.

Step 3 — Scale to per-block rate. The hill value is multiplied by maxFundingFeePerBlock to produce the target rate. The target is clamped to ±maxFundingFeePerBlock:

$$targetRate = \text{clamp}\left(\frac{hillScale}{100} \times hill,\ -1,\ +1\right) \times maxFundingFeePerBlock$$

Step 4 — Smooth convergence. The actual funding rate does not jump instantly to the target. It converges via exponential decay controlled by a spring factor:

$$fr(t) = targetRate + (lastRate - targetRate) \times e^{-sFactor \times \Delta blocks}$$

When the rate crosses zero (sign flip), convergence is 200× faster. When the rate is falling toward a lower target, convergence is 50× slower. This asymmetry means the rate reacts quickly to new imbalances but decays gradually.

What You Pay (or Earn)

$$fundingFee = accumulatedRate \times collateral \times leverage$$

Positive funding fee = you pay (deducted from your trade value at close). Negative = you earn (added to trade value).

Worked example: You're long BTCDOM with $1,000 collateral at 50x. Total position: $50,000. If the accumulated funding rate over your holding period is 0.1%, your funding cost is:

$$0.001 \times 1{,}000 \times 50 = \$50$$

That $50 is deducted from your PnL when you close.

Key Parameters

Tips

• Stay at 20x or below to qualify for the 0.05% maker rate instead of 0.1%.
• Trade with the skew. Opening on the underweight side reduces imbalance and earns you maker pricing.
• Factor fees into risk math. At 250x taker, opening + closing fees alone eat ~50% of collateral. You need a real move to profit.
• Monitor funding direction. If you're on the majority side, funding costs compound over time. Make sure the expected price move justifies the carry.