Which fees and spreads should be checked for a DMA broker?

Direct answer

If you are using a DMA-style (direct market access) broker for FX, check two categories of published costs: (1) the spread and (2) the fee components (often commission and other explicit charges). Then treat the final trading cost as a combination of published pricing plus variable execution outcomes (which depend on market liquidity, volatility, and how orders are handled). Because FX conditions and provider terms can change, you should verify the exact items on the broker’s current pricing schedule and platform/order documentation.

Mechanics and definitions

A spread is the difference between the quoted bid and ask prices for an instrument. In FX trading, your immediate transaction price is effectively influenced by where the bid/ask lands at the moment your order executes.

Fees are explicit charges that may be separated into categories. Common examples are a commission per trade (or per lot), and other charges that are not part of the spread, such as financing/rollover costs for holding positions, plus any account or platform-related fees depending on the provider.

A DMA-style description usually implies an execution path that is closer to market venues and requires you to think about market microstructure effects. Even without assuming real-time data, you can separate what is “published” (spread model, commission schedule, and stated rollover rules) from what is “variable” (how your specific orders fill and at what prices).

Evidence or example (cost components and assumptions)

Here is a provider-neutral way to structure what you should check.

Published spread model

Confirm whether the broker shows a fixed spread, variable spread, or a minimum spread with widening in certain conditions (wording varies).
Record the spread size in typical conditions shown by the broker or historical examples they provide—then treat it as an input, not a guarantee.

Commission and other explicit trade charges

Identify whether commission is charged per trade, per notional, or per lot.
Confirm whether commission is in addition to spread (most often yes, but you must verify the pricing formula).

Financing/rollover and holding costs

If your example includes holding a position, identify how the broker defines rollover/financing charges and when they apply.

Worked example (hypothetical and assumption-based):

Assume an instrument has an expected spread of 0.8 units (any currency/unit consistent with the broker’s quote).
Assume the broker charges commission of C per trade (you insert the broker’s current number).
Your total cost for that round-turn conceptually combines spread impact at execution plus commission, plus any financing if the position is held.
If actual execution deviates (because fills are at different bid/ask moments), then the realized spread impact differs from the expected spread. This is why you verify both published pricing and execution-related documentation.

Limitations and risks (material failure modes)

Spread widening and liquidity changes: Even if a broker publishes a spread range, real quotes can move during volatile moments. Your realized spread impact may be higher than what you used in your assumptions.
Partial fills and fill timing: Orders may fill in multiple parts. Each fill can occur at a different bid/ask level, changing the effective cost compared with a single “expected spread.”
Order handling differences: Execution quality can be affected by how the platform routes and manages orders. The same published pricing can lead to different realized costs depending on timing, slippage, and whether the broker can re-quote or adjust during execution.
Cost items outside spread/commission: Financing/rollover charges and any additional charges may dominate your total cost when trades are held longer. If you ignore them, comparisons become misleading.

Verification or next question

To verify independently, do a “cost checklist” using only the broker’s current published materials:

Capture the exact spread description (variable vs fixed, any stated widening conditions, and the quote currency/unit convention).
Capture the commission formula and the timing of when it is applied (per trade vs per lot vs per notional).
Capture financing/rollover rules if positions may be held.
Capture any other explicit account or platform charges that the broker lists.

Then test your understanding by building a simple, assumption-based total-cost calculation for a round turn.