In plain terms — When you buy or sell, the broker or venue may charge a stated cost: that is the commission. You can find it in the fee schedule and trade record; spread and slippage are different costs.
An execution, often called a fill, is the part of an order that is actually matched in the market. An order may produce one fill, several partial fills, or no fill; the effective commission depends on the rule applied by the broker or trading venue.
How the charge arises
The fee schedule defines the calculation base. A commission may be quoted per order, contract, share, or fill, or as a percentage of notional value, the economic value of the quantity traded. Minimums, caps, volume tiers, charging currencies, and product-specific costs may also apply. None of these structures is universal.
Some electronic markets use a maker/taker model. A maker order adds liquidity to the book, the register of available bids and offers; a taker order matches immediately and consumes available liquidity. A limit order is not automatically maker: if its price crosses an available quote, it can be taker. A partly matched order can contain both a taker portion and a maker portion.
Commission, spread, and slippage
| Component | What to observe | Where to verify it |
|---|---|---|
| Commission | Explicit charge applied under the fee schedule | Confirmation, fill history, account statement |
| Difference between the best bid and offer at a defined time | Order book or contemporaneous market data | |
| Difference between a declared reference and the executed price | Timestamp, chosen reference, and fill |
The spread can affect the price obtained, but it is not a commission line item. Slippage is already embedded in the fill price: deducting it again after calculating the result from executed prices counts it twice.
Reconciliation procedure
- Save the fee schedule and tier that applied when the order was placed.
- Import every fill with its quantity, price, maker/taker role, and currency.
- Match each fill to its charge or any rebate, meaning a credit for supplied liquidity.
- Add entry, partial exits, and closing fills, then compare the total with the confirmation and statement.
If a schedule uses a rate c on notional V, the fill charge is described by
c × V. That is only one structure: a per-contract schedule or a fixed minimum
requires a different base. Round-trip cost, meaning opening and later closing
the position, is the sum of the actual charges on every fill.
Leverage does not make fee schedules identical. Where a venue charges on notional value, increasing exposure with the same capital increases the charging base; posted margin does not replace the value traded.
Technical depth: effective execution cost
Comparing only the published rate can mislead. Tiers may vary with volume, product, account type, or liquidity program, and a partial order may receive different maker and taker treatments. The record should therefore preserve the tier actually applied, not a tier reached after the trade.
A maker rebate does not guarantee a cheaper execution overall. Price can move while the order rests, the order may remain unfilled, and spread or slippage can exceed the credit. Comparing two execution methods requires the explicit charge, achieved price, filled quantity, and completion probability across comparable cases.
Limitation — Rates, tiers, and charging currencies can change. This entry explains how to document costs; it does not replace the applicable fee schedule, trade confirmation, or contractual terms.
Sources
- Investor.gov, How Fees and Expenses Affect Your Investment Portfolio — official SEC material on commissions, markups, markdowns, and other transaction costs.
- FINRA, Are You Checking Your Trade Confirmations? — official material on confirmation data, disclosed charges, and reconciliation with account statements.
- Coinbase, Advanced fees — official venue documentation of maker/taker treatment and partial fills; it is an operational example, not a universal schedule.
- Investor.gov, Executing an Order — official SEC material on differences between a displayed quote and an execution price.