Andrew Left

Andrew Left
Born	Andrew Edward Left 9 7, 1970
Birthplace	Michigan, U.S.
Nationality	American
Occupation	Financial analyst, financial writer, short seller
Known for	Activist short selling, founder of Citron Research
Website	[[citronresearch.com citronresearch.com] Official site]

Andrew Edward Left (born July 9, 1970) is an American activist short seller, financial analyst, and the founder and editor of Citron Research, an online investment research publication formerly known as StockLemon.com. Over a career spanning more than two decades, Left has built a reputation as one of the most prominent and polarizing figures in the world of short selling, publishing investigative reports on publicly traded companies he alleges are overvalued or engaged in fraudulent business practices. His reports have targeted firms across the S&P 500 as well as several Chinese companies listed on American exchanges, citing allegations ranging from pyramid schemes and ineffective products to accounting fraud. In 2017, The New York Times dubbed Left "The Bounty Hunter of Wall Street" for his combative approach to uncovering corporate wrongdoing. His most notable short campaigns include his 2015 report on Valeant Pharmaceuticals, which contributed to a dramatic decline in the company's stock price. Left has been a frequent guest on financial media outlets including CNBC and Bloomberg, where he discusses his investment theses and opinions on stocks. In July 2024, federal prosecutors arrested and charged Left with multiple civil and criminal counts, alleging he illegally manipulated the stock market through his short-selling activities. As of early 2026, the criminal case remains pending after a federal judge rejected Left's motion to dismiss the charges.

Early Life

Andrew Edward Left was born on July 9, 1970, in Michigan, United States. Limited publicly documented information is available about his childhood and family background. Left grew up in Michigan before pursuing higher education on the East Coast.

Education

Left attended Northeastern University in Boston, Massachusetts, where he completed his undergraduate studies. Northeastern is known for its cooperative education program, which integrates classroom study with professional experience. Details regarding his specific degree and year of graduation have not been widely documented in available sources.

Career

Early Career and Founding of Citron Research

Left began his career in the financial industry in the mid-1990s. Before founding Citron Research, Left was involved in commodity futures trading. During this period, the National Futures Association (NFA) sanctioned Left, stating that he "made false and misleading statements to cheat, defraud or deceive a customer in violation of NFA compliance rules." This early regulatory action would foreshadow the contentious relationship Left maintained with regulators and corporate targets throughout his career.

Left subsequently transitioned into equity research and short selling, launching an online investment newsletter initially called StockLemon.com. The publication was later rebranded as Citron Research, under which Left published investigative reports on publicly traded companies he believed were overvalued or engaged in fraudulent practices. The model was straightforward: Left would take a short position in a company's stock, publish a detailed report outlining his thesis for why the stock should decline, and profit if the share price fell. This practice, known as activist short selling, has long been controversial on Wall Street, with proponents arguing it serves as a check against corporate fraud and critics alleging it amounts to market manipulation.

Over the years, Citron Research launched 51 investigative reports against S&P 500 companies, as well as reports on several Chinese companies trading on U.S. exchanges. Left's reports typically cited allegations of pyramid schemes, ineffective products, accounting irregularities, or outright business fraud. Despite being sued by multiple companies for the reports he published, Left has maintained that he has never lost a case in the United States.

Chinese Reverse Merger Companies

Left gained considerable attention in the early 2010s for his reports on Chinese companies listed on American stock exchanges, many of which had entered U.S. markets through reverse mergers. These reports were part of a broader wave of short-seller scrutiny of Chinese firms that raised questions about the reliability of their financial disclosures and the adequacy of U.S. regulatory oversight of foreign-listed companies.

One of Left's most significant and consequential reports on a Chinese company targeted Evergrande Group, a major Chinese property developer. In June 2012, Left published a report through Citron Research alleging fraud at Evergrande, which caused the company's stock to tumble. The report attracted the attention of Hong Kong financial regulators. In 2016, Left was banned for five years by the Hong Kong Market Misconduct Tribunal, chaired by Justice Michael Hartmann, for allegedly disclosing false or misleading information in connection with the publication of his research report on Evergrande, thereby inducing transactions in violation of the Securities and Futures Ordinance. Left and his supporters noted that his fundamental thesis about Evergrande's financial condition was ultimately vindicated — the company later became the centerpiece of a massive debt crisis in the Chinese real estate sector — but his punishment was not rescinded. The Hong Kong ban prohibited Left from trading in the Hong Kong securities market for the duration of the five-year period.

Valeant Pharmaceuticals

Left's most prominent and impactful short campaign was arguably his targeting of Valeant Pharmaceuticals International, a Canadian pharmaceutical company that had become one of the most closely followed stocks on Wall Street. In October 2015, Left published a report through Citron Research comparing Valeant to Enron, the energy company whose 2001 collapse became synonymous with corporate fraud. Left alleged that Valeant was using a specialty pharmacy called Philidor Rx Services to artificially inflate its revenues through questionable distribution practices.

The report had an immediate and dramatic effect. Valeant's stock price plummeted, wiping out billions of dollars in market value. The decline was particularly painful for prominent hedge fund manager Bill Ackman of Pershing Square Capital Management, who held a large long position in Valeant and suffered significant losses as the stock continued to fall.

The Valeant saga continued to unfold in the months that followed. In March 2016, Left declared that Valeant was "uninvestable," citing the company's mounting legal and regulatory problems. The Los Angeles Times and other outlets covered the expanding scandal extensively, noting the broader implications for pharmaceutical pricing practices and corporate governance. Fortune later published a comprehensive timeline of the Valeant scandal, documenting the company's rise and fall.

Valeant's stock, which had traded above $250 per share at its peak, eventually fell below $10. The company was subsequently renamed Bausch Health Companies. The Valeant episode cemented Left's reputation as a formidable force in the short-selling community and demonstrated the power of activist short research to move markets and draw regulatory attention to corporate practices.

Mallinckrodt and Pharmaceutical Pricing

Left also targeted Mallinckrodt Pharmaceuticals, another company that drew scrutiny for its drug pricing practices. In November 2015, Left published a tweet through Citron Research that drew attention to Mallinckrodt's H.P. Acthar Gel, a drug with a price tag of approximately $35,000, bringing the product's cost back into the public spotlight. The report came during a period of heightened public and political scrutiny of pharmaceutical pricing in the United States, and Left's commentary contributed to the ongoing debate about the cost of specialty medications.

Legal Battles and Litigation

Throughout his career, Left has faced numerous lawsuits from companies targeted in his Citron Research reports. Companies that were the subject of negative reports frequently accused Left of defamation, market manipulation, or publishing misleading information intended to profit from declining stock prices. Left has stated that despite being sued multiple times, he has never lost a case in the United States.

One notable case involved GTX Global Corp., which sued Left over a Citron Research report. The case was documented by the Digital Media Law Project as part of its tracking of legal threats against online publishers and commentators.

Left's litigation record extended beyond U.S. courts. His 2016 ban by the Hong Kong Market Misconduct Tribunal in connection with his Evergrande report represented a significant legal setback in a foreign jurisdiction, even as he maintained that his underlying analysis of the company had been correct.

Federal Criminal and Civil Charges (2024–present)

In July 2024, federal prosecutors arrested and charged Left with multiple civil and criminal counts alleging he illegally manipulated the stock market. The charges represented the most serious legal challenge Left had faced in his career and raised broader questions about the boundary between legitimate activist short selling and illegal market manipulation.

Left mounted an aggressive legal defense. He filed a motion to dismiss the criminal case, but on December 30, 2025, a federal judge rejected the motion, allowing the prosecution to proceed. In November 2025, Left took the unusual step of petitioning the Securities and Exchange Commission (SEC) to define what constitutes illegal short-selling activity, framing it as an effort to establish clear legal standards that he argued would demonstrate his innocence.

Institutional Investor reported on Left's petition to the SEC, describing it as a legal gambit aimed at establishing that his trading practices fell within the bounds of permissible market activity.

As of early 2026, Left was preparing for a criminal trial expected later that year. In an unusual development reported by Business Insider in December 2025, Left was found to have been using Claude, an artificial intelligence chatbot, to help prepare for his legal defense. Business Insider obtained transcripts of Left's conversations with the AI, in which he discussed his fraud-trial concerns and legal strategy. The report drew attention both for its revelations about Left's legal preparation and for its illustration of how AI tools were being used in novel ways by individuals facing complex legal proceedings.

Personal Life

Left resides in the United States. Limited publicly documented information is available regarding his personal and family life. He has maintained a relatively private personal life despite his public profile as a financial commentator and short seller. Left's public persona has been defined primarily by his professional activities at Citron Research and his frequent media appearances discussing his investment theses.

Recognition

Left's career as an activist short seller has drawn both praise and criticism from participants in financial markets and the broader public. In 2017, The New York Times profiled Left under the headline "The Bounty Hunter of Wall Street," a moniker that captured both his aggressive approach to uncovering what he considered corporate fraud and the controversial nature of his methods.

His 2015 report on Valeant Pharmaceuticals was widely covered in the financial press. The Wall Street Journal profiled him as "The Short Who Sank Valeant Stock," crediting his Citron Research report with precipitating the dramatic decline in the company's share price. Bloomberg News similarly covered the impact of Left's report on Valeant's stock and on prominent investors who held long positions in the company.

Left's work has also been recognized in the context of broader discussions about the role of short sellers in financial markets. Motley Fool's CAPS platform documented instances where Citron Research's calls were vindicated by subsequent events, lending credibility to Left's investigative approach.

His engagement with prominent investors has also generated media attention. Bloomberg reported in 2013 on the broader ecosystem of activist investors and short sellers in which Left operated, referencing figures such as Carl Icahn in the same financial landscape.

Legacy

Andrew Left's career as an activist short seller has intersected with several major episodes in American and international financial markets. His report on Valeant Pharmaceuticals contributed to one of the most significant corporate scandals of the 2010s and helped bring public attention to pharmaceutical pricing practices that became the subject of congressional hearings and regulatory scrutiny.

His Evergrande report, though it resulted in a five-year ban from the Hong Kong market, proved prescient. Evergrande later became the epicenter of a massive debt crisis in the Chinese real estate sector that had ramifications for global financial markets. The tension between Left's punitive outcome in Hong Kong and the eventual validation of his thesis raised questions about the regulatory treatment of short sellers across different jurisdictions.

The federal criminal charges brought against Left in 2024 have placed him at the center of an ongoing legal and regulatory debate about the boundaries of activist short selling. The outcome of his criminal case, expected to proceed to trial in 2026, may have significant implications for the practice of short-selling research and the extent to which publishing critical research reports while holding short positions constitutes market manipulation or protected financial commentary.

Left's use of AI tools to prepare his legal defense, as reported by Business Insider, has also attracted attention as an early example of the intersection between artificial intelligence and high-stakes legal proceedings in the financial sector.

Citron Research, over its more than two decades of operation, has published investigative reports on dozens of major companies, contributing to broader conversations about corporate governance, financial transparency, and the role of independent research in capital markets.