Sour fees

Schedule

Base trade fee

3 basis points (0.03%) per fill

fee_micros (on-chain)

300

Taker/maker split

None — single rate

Volume tier ladder

None

Token-staking discount

None

Fee destination

100% to the SOUR LP vault (USDC)

Network fee

Standard Solana priority fee, paid by signer

Withdrawal fee

None — only Solana network fee

How it works

When two orders match inside a 1.8-second batch, Sour withholds 3 bps of the fill notional from each side and routes it into the SOUR LP vault. The fee is charged on every fill regardless of position direction, size, or whether you posted the resting order or crossed it.

Because Sour clears the entire batch at one uniform price, there is no maker-taker asymmetry to compensate for: no order in a slot is "ahead" or "behind" any other. A maker-rebate model would just be an accounting transfer with no incentive purpose.

Volume tier ladders are absent for the same reason: the LP is the counterparty, and concentration discounts would push the LP toward adverse selection without buying it any signal value.

Worked examples

• $1,000 fill
  Fee = $1,000 × 0.0003 = $0.30, routed to LP vault.
• $1,000,000 fill
  Fee = $1,000,000 × 0.0003 = $300, routed to LP vault. Same rate as the $1,000 fill.
• Open + close round trip on $10,000 notional
  ~$3 + ~$3 = ~$6 of fees, both flowing into the LP vault.

Funding payments are separate

Funding is not a fee — it is a payment between longs and shorts that anchors the perpetual mark to the spot index. Sour computes funding inside every batch as part of the same atomic settlement; there is no off-chain cron. See the funding explainer.

Funding flows do not pass through the LP vault. They reallocate value between long and short positions directly. The fee is the only number that compensates the LP for risk-bearing.