Insider Trading: Wall Street’s Most Lucrative Crime

Insider trading is the financial crime with the most persistent gap between how often it happens and how often it gets prosecuted. The SEC brings approximately 50 to 60 insider trading cases per year in a market where hundreds of millions of trades occur daily, while academic studies consistently find statistical anomalies in options and stock trading before major corporate announcements at rates that cannot be explained by chance. The cases that define public understanding of insider trading — Ivan Boesky, Raj Rajaratnam, SAC Capital — are worth examining precisely because they reveal the structure of a problem far larger than the individuals prosecuted.

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What the Law Actually Says About Trading on Inside Information

The Securities Exchange Act of 1934 didn’t explicitly prohibit insider trading. The legal prohibition developed through SEC enforcement actions and court decisions over decades. The core principle that emerged: when a corporate insider — an officer, director, employee, or someone who received confidential information from one — trades on material non-public information, they have breached a duty and committed fraud.^1^ “Material” means information that a reasonable investor would consider significant to an investment decision. “Non-public” means it hasn’t been disclosed to the market.

The rules evolved through cases that pushed the boundaries. The Dirks v. SEC decision in 1983 established that tippees — people who receive inside information from insiders — are liable only if the insider personally benefited from passing the information.^1^ The United States v. Newman decision in 2014 temporarily tightened this standard further, requiring prosecutors to show the tippee knew the insider received a personal benefit, before the Supreme Court partly reversed it in Salman v. United States in 2016, holding that a gift of information to a trading relative qualifies as a personal benefit. The law is complicated. The trading is straightforward: someone knows something the market doesn’t, and they trade on it.

How Ivan Boesky’s Cooperation Dismantled 1980s Wall Street

The most significant insider trading prosecution of the 20th century was Ivan Boesky, who built a fortune in the 1980s as an arbitrageur betting on merger outcomes. Boesky was exceptionally successful because he was cheating: he was paying corporate insiders for advance information about pending deals. In 1986, he paid $100 million in fines and penalties to the SEC — at the time the largest settlement in the agency’s history — and agreed to cooperate with investigators.^2^

Boesky was sentenced to three years in federal prison and served approximately two years. His cooperation with prosecutors became the model for white-collar fraud investigations: catch one player, flip them upward. The information he provided enabled the SEC and Justice Department to dismantle what investigators described as a systematic network of insider information flowing through Wall Street’s elite — including Michael Milken’s junk bond operation at Drexel Burnham Lambert.

Raj Rajaratnam and the First Wiretap Case

In 2009, federal prosecutors charged Raj Rajaratnam, founder of the Galleon Group hedge fund, in the first major insider trading case to use wiretap evidence — a technique previously common in organized crime cases but rarely deployed in financial fraud. The recordings captured Rajaratnam receiving tips from sources inside Goldman Sachs, McKinsey, Intel, and other major companies.^3^

Rajaratnam was convicted in May 2011 on 14 counts of securities fraud and conspiracy. He was sentenced to 11 years in federal prison — the longest sentence ever imposed for insider trading at the time — and ordered to pay $93 million in penalties. The Galleon investigation led to more than 60 additional convictions. A tip from Goldman Sachs board member Rajat Gupta about Warren Buffett’s $5 billion Goldman investment in September 2008 — made while Lehman Brothers was collapsing — was among the most prominent tips uncovered. Gupta was convicted in 2012 and sentenced to two years in prison.

SAC Capital and the Culture of “Edge”

Steven A. Cohen’s hedge fund SAC Capital Advisors was, according to federal prosecutors, a culture in which inside information was systematically acquired and traded on over more than a decade. SAC paid $1.8 billion in penalties in 2013 — the largest insider trading settlement in history — and pleaded guilty to securities and wire fraud charges as a firm. Cohen himself was never criminally charged. The SEC brought civil charges against him for failing to supervise employees, resulting in a two-year ban from managing outside money that expired in 2018.^4^

Eight SAC employees were convicted of insider trading. The pattern prosecutors described was one in which Cohen received “edge” — information that provided advantages over other investors — through a network of analysts and portfolio managers who cultivated relationships with corporate employees, consultants, and industry experts in ways that frequently crossed into obtaining material non-public information.

Who Gets Caught Is a Fraction of Who Is Doing It

The people prosecuted for insider trading are disproportionately visible and easy to make into cautionary tales. The academic literature suggests the activity is far more widespread than the prosecution record indicates. A 2010 study published in the Journal of Finance found significant abnormal trading in target company stocks before 25% of merger announcements between 1996 and 2012.^1^

The enforcement gap is structural. Proving insider trading requires establishing that the trader had access to material non-public information and actually used it — a causal chain that is difficult to establish from trading data alone without surveillance evidence like wiretaps, emails, or a cooperating witness. SAC Capital was cracked partly because one employee became a government informant. Boesky’s network was cracked because one of his information suppliers was himself under investigation and cooperated. The prosecutions that happen are often the product of luck as much as investigation.

The SEC has invested in statistical surveillance tools to identify unusual trading patterns before major announcements. The Dodd-Frank Act of 2010 established a whistleblower program that pays informants between 10% and 30% of sanctions collected in cases resulting in over $1 million in penalties — between 2011 and 2022, the SEC paid out more than $1.3 billion in whistleblower awards.^4^ These are real improvements. The most sophisticated insider trading routes through layers of relationships and entities and takes place in markets — particularly options markets and international exchanges — where detection is most difficult. What gets prosecuted is a sample. The LIBOR scandal operated on similar logic: the manipulation was documented in internal communications for years before regulators acted, because the institutions involved were too central to the financial system to scrutinize aggressively.

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Sources:

1. Stewart, James B. Den of Thieves. Simon & Schuster, 1991.
2. Ahern, Kenneth R., and Denis Sosyura. “Who Writes the News? Corporate Press Releases During Merger Negotiations.” Journal of Finance, 2014.
3. United States v. Rajaratnam, No. 09-cr-1184 (S.D.N.Y. 2011).
4. Securities and Exchange Commission. Annual Report to Congress on the Whistleblower Program. SEC, 2022.
5. Kolhatkar, Sheelah. Black Edge: Inside Information, Dirty Money, and the Quest to Bring Down the Most Wanted Man on Wall Street. Random House, 2017.