Automated Execution Systems and Alternative Trading Systems
Beyond traditional exchanges and over-the-counter (OTC) markets, a significant portion of trading now occurs through electronic systems that operate outside the traditional exchange structure.
Electronic Communications Networks (ECNs)
- Electronic systems that automatically match buy and sell orders
- Provide an alternative to traditional exchange trading
- Allow institutional investors to trade anonymously
- Operate as Alternative Trading Systems (ATS) registered under Regulation ATS
- Examples: dark pools, crossing networks
Dark Pools
- A type of ATS that does not display quotes publicly before execution
- Used primarily by institutional investors for large block trades to avoid market impact
- Trades are reported after execution to the consolidated tape (post-trade transparency only)
- Provide anonymity but have raised regulatory concerns about transparency and fairness
Why dark pools exist: When a large institution wants to buy or sell millions of shares, displaying that order publicly would move the market against them. Dark pools allow execution without revealing intent.
Exam Tip: Gotchas
- Dark pools do NOT display pre-trade quotes publicly. However, trades executed in dark pools ARE still reported to the consolidated tape after execution.
- The exam may test the difference between pre-trade and post-trade transparency. Dark pools provide post-trade transparency only.
Regulation ATS
Securities and Exchange Commission (SEC) regulation that governs Alternative Trading Systems:
- ATS operators must register as broker-dealers and comply with fair access, capacity, and reporting requirements
- Financial Industry Regulatory Authority (FINRA) Rule 4551 requires ATS operators to record and transmit order and execution information for regulatory surveillance purposes
- ATS that reach certain volume thresholds must provide fair access to their system (cannot discriminate among qualified participants)
Exam Tip: Gotchas
- ATS operators must register as broker-dealers, not as exchanges.
- Fair access requirements only apply once an ATS reaches certain volume thresholds. Below those thresholds, an ATS can restrict participation.
Regulation NMS (National Market System)
Comprehensive SEC regulation governing the structure of U.S. equity markets:
| Rule | Name | What It Does |
|---|---|---|
| Rule 611 | Order Protection Rule | Requires trading centers to prevent trade-throughs; executing orders at prices inferior to the best available price, known as the National Best Bid and Offer (NBBO), displayed by other trading centers |
| Rule 610 | Access Rule | Limits the fees that trading centers can charge for accessing their quotations |
- Ensures that customers receive the best available price regardless of which market center displays the best quote
- The Order Protection Rule is the backbone of NBBO enforcement
Exam Tip: Gotchas
- Regulation NMS Rule 611 prevents trade-throughs, meaning no trading center can execute an order at a price worse than the NBBO displayed elsewhere.
New York Stock Exchange (NYSE) Automatic Execution Systems
- NYSE Rules 1000-1004 govern automatic execution of orders
- Orders can be executed automatically when they meet specified criteria
- Ensures speed and efficiency of execution on the exchange floor