Fees

The simulator applies a realistic brokerage fee schedule to every order, so your P&L reflects the friction of real trading. Fees aren't an afterthought on a 0DTE strategy: a structure that trades four legs in and four legs out every single day can hand a meaningful share of its gross edge back in commissions, and the platform is deliberately honest about that.

Default schedule

Fee	Amount
Buy to open option	$1.72 per contract
Sell to open option	$1.72 per contract
Buy to close option	$0.72 per contract
Sell to close option	$0.72 per contract
Exercise / assignment	$5.00 per strike

Fees are charged per leg and rolled up onto the order. They're deducted from your P&L and reflected in your buying-power math. (The full schedule also carries two per-share equity fees for completeness, but since trading is 0DTE SPX options only, they never come into play.)

Worked example. A 1-lot iron condor is four contracts to open — 4 × $1.72 = $6.88. Close it early at a profit target and that's four more contracts at 4 × $0.72 = $2.88, for $9.76 round-trip. Let the winning side expire instead and the expiring legs cost nothing; only in-the-money legs settle, at $5.00 per strike.

How fees show up

• For a filled order, fees are the sum of the per-leg charges and are baked into your realized P&L.
• For a pending limit or stop order, the ticket shows an estimate from the schedule based on the legs and quantities — so you can see the projected cost before it fills. The estimate only affects your cash totals once the order actually fills.
• Settlement fees ($5.00 per strike for an exercise or assignment) apply when in-the-money options are settled at the close. Options that expire worthless cost nothing.

Custom fee schedule

Any registered user can override the defaults from Settings → Simulator Costs — useful for modeling a specific broker's actual pricing. Values must be non-negative and are capped at 10× the platform default. The override applies across everything you see: pending-order estimates, fills, end-of-day settlement, per-second history — and every backtest result you view, which is re-costed under your schedule at read time without recomputing anything. You can revert to the defaults at any time.

The same Settings page also holds your slippage setting — the other half of the simulator's execution-cost model.

Tips

• Backtest under the fees you'd really pay. Because results are overlaid with your schedule at read time, switching the schedule instantly re-scores every strategy and portfolio you look at — a two-second way to check whether an edge survives your broker's pricing.
• Closing costs less than opening (by default). The default schedule charges $1.72 to open and $0.72 to close, mirroring brokers that discount closing trades. Strategies that exit early rather than settle pay $0.72 per contract instead of risking a $5.00 per-strike settlement fee on ITM legs — worth remembering when a position is hovering near the money into the close.
• Fees compound with frequency, not size. Ten 1-lot condor days cost the same in fees as one 10-lot day, but spread the market risk differently. When comparing strategies with different trade frequency, look at the fees column of the results day list — it's reported separately from gross P&L for exactly this reason.