A new customer has just been onboarded in a securities firm. After a few weeks, there are unusual trading patterns that are being flagged. Which pattern is most concerning to the compliance officer?

The most concerning pattern is the systematic accumulation of a low-volume security in small increments. This activity is a classic indicator of the initial phase of a "pump and dump" market manipulation scheme. By purchasing shares in small amounts over time, the manipulator can build a large, controlling position in an illiquid stock without causing a sudden price spike that would alert other market participants. This deliberate, methodical accumulation is a strong red flag for a pre-planned effort to artificially inflate the stock's price before selling (dumping) it to unsuspecting investors.

A. Trading large, liquid securities is a normal and common market activity and is not inherently suspicious.
B. While repeated trading in low-priced stocks is a red flag, option D describes a more specific and methodical pattern of manipulation.
C. Multiple incoming wires can be a red flag for layering, but they are less specific to securities market manipulation than the trading pattern in D.

1. Financial Action Task Force (FATF). (2009, October). Money Laundering and Terrorist Financing in the Securities Sector. p. 29, para. 101. The report identifies "transactions that appear to be laying the groundwork for a market manipulation scheme" as a key red flag.

2. ACAMS. (2020). CAMS6 Certified Anti-Money Laundering Specialist Study Guide. Chapter 2, p. 113. The guide lists "purchasing large volumes of low-priced securities" as a red flag for pump-and-dump schemes.

3. International Organization of Securities Commissions (IOSCO). (2013, March). Library of Suspicious Transaction and Order Reports. Report FR03/13, p. 11. Describes a case of layering/market manipulation involving placing small orders to build a position.