How fees work

Engine charges one fee, and only one fee: a performance fee on the new profits the agent generates for you.

If your agent makes you money, we take a cut. If it doesn't, we don't get paid. That's the model. The rest of this page is the detail.

The performance fee

10% of new profits, calculated monthly, paid in USDC, with a high-water mark.

The high-water mark is the highest end-of-month NAV your account has ever reached. We only earn on gains above that mark.

A worked example:

• Your account ended last month at $50,000, your high-water mark.
• This month, the agent grows it to $52,000.
• You've made $2,000 in new profits.
• Engine's fee: 10% of $2,000 = $200, debited from your vault on the first of the next month.
• Your new high-water mark: $52,000.

If next month the account ends at $48,000 (below your high-water mark), there's no fee. We don't earn again until the agent gets you back above $52,000.

This protects you from paying twice on the same gains. It also gives us a real reason to keep the agent sharp, because every dollar of fee we collect is a dollar you actually made.

What we don't charge

• No subscription. No monthly minimum. You can fund $500 and run the agent for free until it makes you money.
• No deposit or withdrawal fees from Engine. (You'll pay network gas for the on-chain steps; see below.)
• No fee on losing months.
• No per-trade or per-tick fee. It doesn't matter how often the agent acts.
• No spread markup. The price you see is the price the agent fills at, minus Hyperliquid's published trading fee. Engine doesn't add anything in between.
• No setup, onboarding, or "premium tier" fee. One performance fee, that's it.

Costs that aren't ours

Trading on Hyperliquid involves real costs that we don't set and don't collect:

• Hyperliquid trading fees. A small maker rebate or taker fee on every fill, currently in the 2–4 basis-point range. Set by the venue.
• Funding payments. The hourly long/short transfer that keeps perps tethered to spot. Goes between traders, not to anyone, and depending on your position, it can be a cost or a credit.
• Network gas. Arbitrum gas to deposit USDC and to withdraw it. Paid to the network at the prevailing rate.
• Slippage. The difference between the displayed price and the actual fill, especially on larger orders. The agent works to minimize this with small order splits, IOC routing, and conservative slip tolerance, but it can't eliminate it entirely.

Engine doesn't add a markup to any of these. Hyperliquid's published rates are what you pay.

Marketplace strategies

If you fork a marketplace strategy and run it on your own account, fees work exactly as above: Engine's standard 10% performance fee on your gains, nothing else.

If you subscribe to a marketplace strategy (you ride the author's published version), the author may take a share of your profits. The author sets the percentage when they publish, capped by the marketplace at 20% of subscriber profit. Engine keeps 20% of the author's collected fee, so on a 20% subscriber fee, the author earns 16%, Engine earns 4%, and you keep 80%.

Subscribers do not additionally pay Engine's standard 10% performance fee. The marketplace fee is the only one on subscribed strategies. We don't double-dip.

Mode	What you pay	Where it goes
Own strategy	10% of new profits	100% Engine
Forked strategy	10% of new profits	100% Engine
Subscribed strategy	Up to 20% of new profits (author sets)	80% author, 20% Engine

Where to see your fees

Settings → Billing shows:

• Your current high-water mark.
• New profits this month.
• Estimated fee at month-end (updates daily).
• Past invoices and the fee that was actually debited each month.

Fees are debited from your vault on the first of each month, in USDC, after the prior month's NAV is settled. The transaction shows up in your decision log like any other.

Why this model

We picked a high-water-mark performance fee deliberately. Subscriptions don't align incentives: a subscription is paid whether the product works or not. A flat per-trade fee rewards us for making the agent over-trade, which is the opposite of what we want.

A high-water-mark performance fee is the standard hedge-fund model for the same reason: we get paid when, and only when, we get you somewhere you've never been before. That's the relationship we want to have with you.