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Key Takeaways
- An internalizer executes customer interest within a broker-dealer.
- A wholesaler can take the other side of an order routed by a retail broker.
- The worked fill improves the $25.28 offer by $0.008 per share.
- All 800 shares cost $20,217.60, saving $6.40 against that offer benchmark.
- Listed-options facilitation follows exchange exposure and crossing rules.
What is order internalization?
Order internalization is the practice of a broker-dealer executing customer orders within its own business, against its inventory or in-house order flow, instead of sending them to a public exchange. In a principal execution, the dealer takes the other side of the trade and manages the resulting inventory.
A retail broker can route an order to a wholesale market maker for this service. The retail broker routes the order, the wholesaler executes it, and a FINRA reporting facility prints it to the tape.
Formula
Buy quote improvement = (reference offer − fill price) × shares; sell quote improvement = (fill price − reference bid) × shares- Use the quote and reference event the execution-quality measure defines.
- Rule 605 price-improvement measurements use the quote at order receipt.
- The worked example fixes the reference offer at $25.28.
- Size improvement compares executed quantity with the displayed quantity at the reference price.
Order internalization example: price and size improvement
A retail trader submits a marketable buy for 800 XYZ shares. At the example’s receipt reference, the quote is $25.26 bid and $25.28 offered, with 300 shares displayed at the offer. A wholesale market maker fills all 800 at $25.272.
- Offer benchmark: 800 × $25.28 = $20,224
- Completed fill: 800 × $25.272 = $20,217.60
- Quote improvement: $0.008 × 800 = $6.40
- Filled quantity beyond the displayed offer size: 800 − 300 = 500 shares
The 800-share fill costs $20,217.60 and improves the $25.28 offer benchmark by $6.40. It fills 500 more shares than the displayed 300-share offer. The execution record establishes price and quantity; the dealer’s offsetting transactions establish its resulting spread capture and inventory.
The fill sets your price and quantity. What the dealer earns depends on how it later offsets that inventory.
How internalized trades are reported, and what Rules 605 and 606 disclose
Rule 606 reports describe broker routing destinations and material compensation arrangements. Rule 605 reports measure execution quality across a market center’s covered orders, against the quote at order receipt.
An off-exchange equity print enters the transaction record through the applicable FINRA reporting facility. Read its price, size and trade conditions alongside the quote and surrounding executions.
Internalization in listed options: Cboe AIM
Listed-options facilitation follows exchange exposure and crossing rules. Cboe AIM is one mechanism: it accepts paired agency and initiating interest for a 100-millisecond auction.
At the best price, the initiating participant’s allocation depends on customer priority and competing responses. The stated 40% or 50% participation right applies to the corresponding competition scenario.
Options flow shows each contract’s trade conditions, price and size across the strikes and expirations relevant to a position.
Limitations of order internalization data
- Name the reference with every improvement figure. The worked $6.40 uses a fixed $25.28 offer; Rule 605 measures use the quote at order receipt, so a quote that moved before receipt gives a different figure.
- Judge your execution by your own fill: $20,217.60 for all 800 shares. The dealer’s spread capture comes from its later offsetting trades.
- Read Rule 606 for where your broker routes and what it is paid, Rule 605 for how each market center executes covered orders, and your own fills for each order’s outcome.
- Read the AIM allocation from the fill report. In Cboe AIM, the 40% or 50% figure is the initiator’s participation right for its competition scenario; customer priority and competing size set the final allocation.
Bottom line
Order internalization means a broker-dealer, often a wholesale market maker, fills a customer order itself instead of sending it to an exchange. Judge it by the execution: compare the fill with the quote at order receipt, check the size filled beyond the displayed quote, and read the broker’s Rule 606 report and the applicable Rule 605 reports.
Clear answers
Frequently Asked Questions
Sources and Further Reading
- SEC: Trade Execution, What Every Investor Should Know
- SEC: Responses to Frequently Asked Questions Concerning Rule 606 of Regulation NMS
- SEC: Frequently Asked Questions Concerning Rule 605 of Regulation NMS
- Cboe: U.S. Options Exchange Crossing Orders (AIM)
- Schwab: Understanding Price Improvement
How entries are sourced, calculated and updated: editorial methodology.