Most traders choose a platform based on its interface or a friend’s recommendation. But the single most important factor i.e. how your order is actually handled is almost always buried in the fine print.
Every trading platform has an execution model: the path your order travels from the moment you click “buy” or “sell” to the moment it is filled. This model determines your spread costs, whether a conflict of interest exists, how quickly your order executes, and the quality of price you receive.
There are five execution models you need to know: DMA, ECN, STP, Market Maker, and NDD. This guide explains each one in plain language with order flow diagrams, identification checklists, a master comparison table, and a trader profile matrix so you can match the right model to your trading style.
1. Direct Market Access (DMA)
Orders routed straight into a real exchange order book
DMA lets you place orders directly into a regulated exchange’s order book, the same infrastructure used by banks and institutional investors. You see real bids and offers from other market participants, and your order interacts with them without any intermediary. Think of it as bypassing the middleman entirely and speaking directly to the market.
Order flow
Your order → Broker DMA gateway → Exchange order book → Matched with real participant
Advantages
- Full market depth visibility (Level 2)
- No conflict of interest
- Price improvement possible
- Institutional-grade transparency
Disadvantages
- High minimum capital often required
- Commission charged per trade
- Not available for OTC forex markets
- Steeper learning curve
How to identify a genuine DMA broker
- Execution policy names a specific regulated exchange (e.g., LSE, NYSE, ASX) as the destination
- Platform displays real Level 2 market depth — actual bids and offers from named participants
- Charges a per-trade commission (not just a spread) — DMA brokers earn from commission, not spread markup
- Offers direct order types: limit orders visible in the real order book, iceberg orders, etc.
- Regulated by a tier-1 authority: FCA (UK), ASIC (Australia), MAS (Singapore), SEC/FINRA (US)
2. Electronic Communication Network (ECN)
Orders matched in a competitive pool of liquidity providers
An ECN connects your order to a network of liquidity providers — banks, hedge funds, other brokers, and sometimes other retail traders, and fills you at the best available price from that pool. The ECN broker earns a fixed commission per trade. Because the broker does not profit from your spread, there is no structural conflict of interest; the broker makes the same money whether your trade wins or loses.
Order flow
Your order → ECN matching engine → Banks / funds / participants (open pool) → Best price filled
Advantages
- Raw spreads (near zero on majors)
- No conflict of interest
- Anonymous order matching
- Fast execution, low slippage
Disadvantages
- Commission adds to cost for small traders
- Variable spreads widen in low liquidity
- Not beginner-friendly
- Requotes still possible in thin markets
How to identify a genuine ECN broker
- Spreads on major pairs start at 0.0–0.2 pips; genuinely raw, not rounded or artificially fixed
- A separate, stated commission per lot (e.g., $3–$7 per side); this is the broker’s revenue model
- Execution policy names multiple external liquidity providers, not just “internal liquidity”
- Platform shows variable depth of market with multiple price tiers from different providers
- The broker publishes slippage statistics; positive slippage (filled better than quoted) should occur sometimes
- Scalping and high-frequency strategies are explicitly permitted in the broker’s terms
3. Straight Through Processing (STP)
Automated routing to a fixed panel of liquidity providers (LP)
STP means your order is processed automatically without a human dealer touching it and sent to one or more pre-selected liquidity providers. Unlike ECN (which uses an open, competitive network), STP brokers route to a smaller fixed panel of banks or prime brokers, and add a markup to the spread they receive. That markup is the broker’s primary revenue.
Order flow
Your order → Automated router → Fixed LP panel (1–5 banks) → Filled at LP price + markup
Advantages
- No dealing desk; automated execution
- Often no separate commission
- Suitable for intermediate traders
- Wider asset coverage than pure ECN
Disadvantages
- Spread markup is the hidden cost
- Fewer LPs = less competitive pricing
- Broker profits from wider spreads
- Execution quality depends on LP relationships
How to identify an STP broker
- Claims “no dealing desk” but does not charge a separate commission; revenue comes from the spread markup
- Spreads are variable but wider than a genuine ECN (typically 0.6–1.5 pips on EUR/USD)
- Execution policy mentions routing to liquidity providers but does not name an open ECN network
- Hedging and scalping may or may not be permitted; check terms carefully
- May offer both a “standard” (STP, spread-only) and “raw” (ECN, commission) account type
4. Market Maker (MM) — (Dealing Desk)
Broker takes the opposite side of your trade internally
A Market Maker (also called a Dealing Desk or “B-book” broker) does not send your order to the external market. Instead, it creates an internal market and takes the opposite side of your trade itself. When you buy, the broker sells to you. When you sell, the broker buys from you.
This creates a structural conflict of interest: the broker profits directly from your losses. This does not make every market maker dishonest, many are well-regulated and provide fair pricing, but it is a conflict that must be understood and managed.
Order flow
Your order → Broker dealing desk → Broker takes opposite side
A-book vs B-book — what brokers don’t advertise
Most brokers run a hybrid: profitable or sophisticated traders are “A-booked” (routed to the real market), while less experienced traders are “B-booked” (kept in-house). This is legal in most jurisdictions but rarely disclosed proactively. You can ask your broker directly. A regulated broker must answer honestly.
Advantages
- Fixed spreads — predictable costs
- No commission — simpler fee structure
- Always provides liquidity — no order rejection
- Beginner-friendly platforms and tools
Disadvantages
- Structural conflict of interest
- Possible requotes and execution delays
- Scalping often restricted or banned
- Unregulated MMs carry high fraud risk
How to identify a Market Maker broker
- Execution policy states the broker “may act as principal” or “may take the other side of your trade”
- Spreads are fixed or unusually stable; real markets are always variable
- No commission charged; revenue comes from the spread between buy and sell prices
- Scalping strategies explicitly restricted or prohibited in the terms of service
- Platform does not show external market depth, only the broker’s own quoted prices
Red flag: slippage always goes against you, stop-loss levels are consistently hit, or withdrawals are delayed when profitable
5. No Dealing Desk (NDD)
Umbrella term — ECN or STP with no human dealer intervention
NDD is not a standalone routing mechanism. It is a structural description meaning no human dealer manually handles your orders. Any broker using ECN or STP technology can legitimately call itself NDD. The practical implication: your orders cannot be subject to dealer discretion, selective re-quoting, or rejection. This matters most during high-volatility events when dealing desk brokers have the greatest incentive to intervene unfavourably.
Order flow
Your order → Automated ECN or STP engine → External liquidity — no dealer touch
Advantages
- No human dealer can intervene
- Faster, more consistent execution
- Scalping and news trading allowed
- No conflict of interest
Disadvantages
- Variable spreads — widen in volatility
- “NDD” is often used loosely by brokers
- Some brokers B-book despite claiming NDD
- Less suitable for very small accounts
How to identify a genuine NDD broker
- Terms explicitly state “no dealing desk” and describe automated routing to external LPs
- All order types including market orders during news events are executed at the next available price without requote
- Scalping and news trading are permitted in the terms of service
- Published execution statistics show both positive and negative slippage; real NDD includes both
Watch out: some brokers claim NDD but still B-book a portion of flow. Ask for written confirmation of execution method per account type.
Master comparison: all five models side by side
| Model | Where order goes | Conflict of interest | Spread type | Commission | Scalping | Min. capital | Best regulated by |
| DMA | Real exchange order book | None | Raw / variable | Yes | Yes | $10,000+ | FCA, ASIC, MAS, SEC |
| ECN | Open LP pool (OTC) | None | Raw / near-zero | Yes | Yes | $200–$1,000 | FCA, ASIC, CySEC, MAS |
| STP | Fixed LP panel | Minimal | Variable + markup | Sometimes | Usually yes | $100–$500 | FCA, ASIC, CySEC, FSCA |
| MM | Internal dealing desk | Yes | Fixed or variable | Rarely | Often restricted | $0–$100 | Verify carefully |
| NDD | ECN or STP (automated) | None | Variable | Depends | Yes | $200+ | FCA, ASIC, CySEC |
Trader profile matrix — which model suits you?
Match your trading style and experience level to the right execution model.
Profile 1 – Complete Beginner
New to trading. Small capital (under $500). Trades infrequently. Values simplicity over cost efficiency.
Best fit:
Market Maker – Fixed spreads, no commission, and beginner-friendly platforms. Choose a well-regulated MM
Avoid:
ECN — commission erodes small accounts
Profile 2 – Casual / Part-Time Trader
Trades a few times per week. Swing or position trader. Holds trades hours to days. Capital $500–$5,000.
Best fit:
STP/ NDD – No dealing desk removes conflict of interest. Variable spreads are manageable at lower trade frequency. Often no commission.
Avoid:
Unregulated MM
Profile 3 – Active Day Trader
Trades multiple times daily. Scalping or intraday strategies. Cost-sensitive. Capital $2,000–$20,000.
Best fit:
ECN/ NDD – Raw spreads dramatically reduce per-trade cost at high frequency. Commission is cheaper than wide spreads when scalping.
Avoid:
MM — scalping often banned
Profile 4 – Algorithmic / Quant Trader
Uses automated trading systems or EAs. Requires API access, low latency, and consistent execution. Volume-focused.
Best fit:
DMA/ ECN – DMA and ECN offer the lowest latency, most consistent execution, and genuine market depth. API and FIX protocol access standard.
Avoid:
MM — execution unpredictable
Profile 5 – Professional / Institutional
High capital ($50,000+). Needs best execution, full market depth, regulatory protection, and complete price transparency.
Best fit:
DMA/ ECN – DMA provides institutional-grade execution with full order book access. ECN provides the best OTC pricing. Both operate under the highest regulatory standards.
Avoid:
MM / unregulated platforms
