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Dark Pools

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Overview

Dark pools are private trading venues where orders are not displayed publicly before execution. They provide anonymity and reduced market impact for large institutional orders.

Types of Dark Pools

Type Operator Example
Broker-Dealer Investment banks Goldman Sachs Sigma, MS Pool
Exchange-Affiliated Public exchanges NYSE Dark, NASDAQ Crossfinder
Independent Standalone firms Liquidnet, POSIT
Internalizer Retail brokers Citadel Securities, Virtu

How Dark Pools Work

1. Institutional trader sends order to dark pool
2. Order is NOT displayed publicly
3. Dark pool searches for matching contra-side order
4. If match found → trade executes at midpoint or better
5. Trade reported to consolidated tape (delayed)

Advantages

Benefit Description
Anonymity Order not visible to market
Reduced Impact Less market impact than lit exchanges
Price Improvement Often executes at midpoint
Lower Information Leakage HFTs can't see your order

Disadvantages

Drawback Description
No Guaranteed Execution May not find matching order
Less Price Discovery Orders hidden from market
Adverse Selection May trade against informed flow
Opacity Less transparent pricing

Dark Pool Volume

US Equity Dark Pool Volume: ~30-40% of total volume

Largest venues by volume:
1. Citadel Securities
2. Virtu Financial
3. Jane Street
4. UBS ATS
5. Goldman Sachs Sigma X

Trading Strategy Implications

For All Traders

  • Dark pool prints at unusual prices can signal institutional activity
  • Large dark pool trades may indicate smart money positioning
  • TRF volume spikes = institutional activity

Regulation

Reg ATS (Alternative Trading Systems)

Dark pools must register as ATS if they:
- Match orders internally
- Handle > 5% of average daily volume

Requirements:
- Fair access rules
- Reporting requirements
- SEC oversight

Practical Guidelines

  1. Not for Retail — Most dark pools have minimum order sizes
  2. Use Smart Routing — Brokers automatically route to dark pools
  3. Monitor TRF Prints — Can signal institutional activity
  4. Understand Fill Rate — Dark pools don't guarantee fills
  5. Price Discovery — Dark pools reduce market transparency

Next Steps