Order execution unlocked: how your “Buy” button connects to global markets

You’ve analyzed the charts, set your stop-loss, and with a mix of conviction and adrenaline, you click the “Buy” button. In that instant, a complex, high-stakes, and often invisible machinery kicks into gear. The journey of your order from your screen to the global marketplace is a fascinating tale of technology, finance, and speed. Let’s demystify the order execution process in Forex and other asset trading.

What happens when you click buy: a step-by-step flow

1. The command: your broker’s platform
When you click, your trading platform (like MetaTrader, cTrader, or a broker’s proprietary software) packages your order details: asset, volume, direction (buy/sell), order type (market, limit, etc.), and any attached conditions. This data packet is encrypted and sent to your broker’s order routing server in milliseconds.

2. The gatekeeper: the broker’s liquidity strategy
This is where broker models diverge significantly, impacting your trade’s cost and outcome.

• Dealing desk (DD) / market maker: Some brokers act as the counterparty to your trade internally. They may hedge the aggregate risk of their clients’ positions later in the real market. This can offer fixed spreads and guaranteed stop-losses but introduces a potential conflict of interest, as the broker may profit from client losses.
• No dealing desk (NDD): Most modern retail brokers use this model. Your order is not kept internally but is immediately passed on.
  • Straight through processing (STP): The broker routes your order directly to one or several of their liquidity providers (LPs)—large banks (like JPMorgan, Citi), hedge funds, or electronic communication networks (ECNs).
  • Electronic communication network (ECN) / Direct market access (DMA): This is the most transparent model. Your order is placed into a central electronic pool with orders from other participants (banks, institutions, other traders). The system matches buy and sell orders directly. You see the raw interbank spread plus a small broker commission.

3. The arena: liquidity providers and the market
At the LP or ECN, your order seeks a match. For a forex market order to buy EUR/USD, the system scans available sell orders from its network. It fills your order at the best available price(s). If your 1-lot order is filled by five different LPs offering slightly different prices for smaller volumes, you get an average price—this is price aggregation, a benefit of good NDD brokers.

4. The confirmation: the loop closes
A fill confirmation, with the exact execution price, rockets back through the network to your broker’s server and finally to your platform. Your “Open Position” appears, and your P/L starts fluctuating. This entire process, from click to confirmation, should take less than 100 milliseconds with a quality broker.

Key concepts that affect your trade

➡ Forex brokers’ slippage: causes and how to minimizethe  impact

• Slippage: The difference between your requested price and the actual execution price. Common during high volatility (news events) when prices move rapidly. It can be negative (worse price) or sometimes positive (better price).
• Requotes: A hallmark of poor execution or low liquidity. Instead of filling your order, the broker “asks” if you accept a new, worse price. This indicates the broker couldn’t execute at your price and is offering a manual workaround.
• Partial fills: Your large order is filled in several chunks at different prices as liquidity becomes available.

Why execution quality matters: a concrete example

Imagine you buy 10 lots of GBP/USD at a market price quoted as 1.2500.

• Broker A (Poor NDD): Has few LPs. Your large order causes a minor “price impact,” and you get filled at an average of 1.2503. You start with 3 pips of “loss” built into the trade.
• Broker B (Quality ECN): Has deep, tier-1 liquidity. Your order is split and instantly matched across dozens of banks. Your average fill is 1.25005. You start with only 0.05 pips of cost.

Over dozens of trades, these microscopic differences compound significantly, affecting your long-term profitability.

What happens when you click buy: a real trading example

Let’s walk through exactly what happens in that critical second after you click “Buy,” using a realistic scenario.

Trader: Alex
Asset: EUR/USD
Broker: Pepperstone (ECN Model)
Order: Market Buy for 2 standard lots (200,000 units)
Time: 10:00 AM London session (moderate volatility)

Step-by-step execution flow:

1. The click (T+0ms ((T+) marks the stopwatch start from your trade click, measuring every critical millisecond of its journey to execution, where speed is the invisible currency of modern markets. If you click “Buy” at T+0ms, your order might reach liquidity providers at T+15ms, get filled at T+40ms, and appear in your account by T+80ms.)): The clock starts. Your finger releases the mouse button or lifts off the touchscreen. The electrical signal is sent:
Alex sees EUR/USD quoted at 1.0875 / 1.0876 (Bid/Ask) on his cTrader platform. He clicks “Buy at Market.”

2. Order routing (T+5ms):
The order is encrypted and shot from Alex’s computer in Frankfurt to Pepperstone’s matching engine in the LD4 data center in London.

3. Liquidity aggregation (T+15ms):
Pepperstone’s system doesn’t send this to a single bank. Instead, it fragments the 2-lot order and routes it simultaneously to its 15+ tier-1 liquidity providers (like JPMorgan, Citi, UBS) and multiple ECNs.

At this exact millisecond, the available liquidity in the market looks like this:

4. Order matching (T+40ms):
The system follows price-time priority: it fills at the best (lowest) available Ask prices first.

• First fill: 0.3 lots @ 1.08760 (from Bank B – best price)
• Second fill: 0.5 lots @ 1.08761 (from Bank A)
• Third fill: 1.2 lots @ 1.08762 (0.8 from ECN Pool 1 + 0.4 from ECN Pool 2)

Total: 2.0 lots filled.

5. Price calculation (T+45ms):
The system calculates Alex’s average execution price:

• (0.3 × 1.08760) + (0.5 × 1.08761) + (1.2 × 1.08762) / 2.0
• = 1.087615 (rounded to 1.08762 on most platforms)

6. Confirmation (T+80ms):
A fill confirmation flies back to Alex’s cTrader platform. His position opens:

• Executed at: 1.08762
• Slippage: +0.2 pips (BETTER than the quoted 1.08766 Ask)
• Cost: Pepperstone’s commission of $7 per lot × 2 = $14
• Effective spread: (1.08762 – 1.0875) × 10,000 = 1.2 pips including commission

7. The alternative scenario: what could go wrong?
If Alex had used a broker with poor liquidity during a volatile news event (like the NFP report), the process might look very different:

• Quoted price: 1.0875/1.0876
• Click “Buy” → Order processes slowly
• During the 200ms delay, prices jump to 1.0880/1.0881
• Fill: 1.0881 with negative slippage of 5.1 pips
• Result: Alex starts his trade $102 in the red just from execution

Top 5 FX and CFD brokers with robust order execution

Here are 5 brokers known for their robust order execution models:

Pepperstone

• Execution model: True ECN/DMA model pioneer.
• Why it stands out: Renowned for razor-sharp raw spreads from 0.0 pips and ultra-fast execution via its data centers in London and New York. Offers both MT4/5 and cTrader, with cTrader providing exceptional transparency into depth of market (DOM). Its focus is purely on providing institutional-grade access to retail traders.
• Best for: Serious traders (scalpers, algos) who prioritize execution speed and lowest trading costs over bells and whistles.

FP Markets

• Execution model: Advanced NDD with ECN pricing.
• Why it stands out: Consistently praised for its institutional-grade execution. Offers true raw spreads from 0.0 pips on its IRESS platform and ECN accounts. Connects to deep liquidity pools, resulting in minimal slippage. A strong alternative to Pepperstone, especially for Australian and European traders.
• Best for: Traders seeking a reliable, no-nonsense ECN environment across forex, equities, and commodities.

BlackBull

• Execution model: Prime ECN NDD.
• Why it stands out: A true ECN broker focusing on serving professional and high-volume traders. Provides direct access to tier-1 bank liquidity, resulting in tight spreads and high execution speeds. Its relatively lean corporate structure is designed to pass on liquidity advantages directly.
• Best for: Higher-volume traders and those using automated strategies who need stable, direct market access.

XM Group

• Execution model: Hybrid (Offers both NDD and market maker execution depending on account type).
• Why it stands out: While not a pure ECN, XM is a global giant known for reliable execution with no requotes as a core policy. It provides a variety of account types (Micro, Standard, Ultra Low) catering to different trader sizes. Its strength lies in stability, a vast range of instruments, and excellent customer support.
• Best for: Beginner to intermediate traders and those who value a wide range of deposit methods and flexible account options over the absolute tightest spreads.

eToro

• Execution model: Unique market maker/social trading hybrid.
• Why it stands out: Its execution is tailored to its social and copy-trading ecosystem. When you “copy” a trader, eToro bundles all copiers’ orders and executes them as a single block, aiming for a fair average price. For standard trades, it uses a combination of internal matching and external LPs. The priority is user experience and social features, not ultra-low latency.
• Best for: Social traders, beginners learning by copying, and those interested in stocks and crypto CFDs alongside forex.

Risk disclaimer: eToro is a multi-asset platform which offers both investing in stocks and cryptoassets, as well as trading CFDs.

CFDs are complex instruments and come with a high risk of losing money rapidly due to leverage. 61% of retail investor accounts lose money when trading CFDs with this provider. You should consider whether you understand how CFDs work, and whether you can afford to take the high risk of losing your money.

This communication is intended for information and educational purposes only and should not be considered investment advice or investment recommendation. Past performance is not an indication of future results.

Copy Trading does not amount to investment advice. The value of your investments may go up or down. Your capital is at risk.

Don’t invest unless you’re prepared to lose all the money you invest. This is a high-risk investment and you should not expect to be protected if something goes wrong. Take 2 mins to learn more.

eToro USA LLC does not offer CFDs and makes no representation and assumes no liability as to the accuracy or completeness of the content of this publication, which has been prepared by our partner utilizing publicly available non-entity specific information about eToro.

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