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

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. Through Citron, Left has published investigative reports on publicly traded companies he alleges are overvalued, engaged in fraud, or operating under questionable business practices. His reports have targeted firms across the S&P 500 as well as several Chinese companies listed on American exchanges, and his research has at times precipitated significant declines in the share prices of his subjects. Left has been a frequent commentator on financial media outlets including CNBC and Bloomberg, where he has discussed his views on specific stocks and the practice of short selling more broadly. In 2017, The New York Times referred to him as "The Bounty Hunter of Wall Street." Left's career has been marked by both notable successes—including his prescient short position in Valeant Pharmaceuticals—and significant legal challenges, including a five-year ban from trading in Hong Kong and, in 2024, federal criminal charges alleging securities fraud and market manipulation. As of early 2026, Left faces an ongoing criminal trial in the United States.

Early Life

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

Education

Left attended Northeastern University in Boston, Massachusetts, where he completed his undergraduate studies. Northeastern's cooperative education program, which integrates academic instruction with professional work experience, provided Left with early exposure to the financial industry.

Career

Early Career and National Futures Association Sanction

Left began his career in the financial industry in the mid-1990s. Before establishing Citron Research, Left was involved in futures trading. During this period, the National Futures Association (NFA), a self-regulatory organization for the U.S. derivatives industry, sanctioned Left. The NFA stated that Left "made false and misleading statements to cheat, defraud or deceive a customer in violation of NFA compliance rules." This early regulatory action would foreshadow Left's contentious relationship with financial regulators throughout his career.

Founding of Citron Research

Left founded his online investment research publication initially under the name StockLemon.com before rebranding it as Citron Research. The publication became Left's primary vehicle for disseminating investigative reports on publicly traded companies. Operating as an independent research outlet rather than through a traditional Wall Street institution, Citron Research occupies a niche in the financial ecosystem as an activist short-selling publication. Left's model involves conducting research on companies he believes are overvalued or engaged in fraudulent practices, publishing his findings, and taking short positions that profit if the targeted company's stock price declines.

Over the course of its operation, Citron Research launched 51 investigative reports against S&P 500 companies. The reports have cited a range of allegations, including pyramid schemes, ineffective products, and accounting or business fraud. Left has also targeted several Chinese companies listed on U.S. exchanges, contributing to a broader wave of scrutiny over the financial reporting practices of Chinese firms seeking access to American capital markets.

Despite being sued by multiple companies in response to the reports he has published, Left has maintained that he has never lost a case in the United States.

Evergrande Group Report and Hong Kong Ban

In June 2012, Citron Research published a report on Chinese property developer Evergrande Group, alleging the company was engaged in fraud. Following the publication of the report, Evergrande's stock price fell significantly.

The Hong Kong Market Misconduct Tribunal, chaired by Justice Michael Hartmann, subsequently investigated Left's report. In 2016, the Tribunal banned Left from trading in Hong Kong markets for a period of five years. The Tribunal found that Left had disclosed false or misleading information in connection with the Evergrande report, thereby inducing transactions in violation of the Securities and Futures Ordinance. Left's case was notable because although his underlying thesis about Evergrande's financial condition was later vindicated—the company would eventually default on its debts in a spectacular collapse that reverberated through global financial markets—his punishment was not rescinded. The case highlighted the tension between the substance of short-seller research and the methods used to disseminate it.

Valeant Pharmaceuticals

Left's most prominent and consequential research campaign was directed at Valeant Pharmaceuticals International (later renamed Bausch Health Companies). In October 2015, Citron Research published a report comparing Valeant's business practices to those of Enron, the energy company whose accounting fraud led to one of the largest corporate collapses in American history. Left alleged that Valeant's relationship with specialty pharmacy Philidor Rx Services constituted a scheme to inflate revenue figures and that the company's broader business model of acquiring other pharmaceutical firms and dramatically raising drug prices was unsustainable.

The Citron report had an immediate and dramatic effect on Valeant's stock price. Billionaire hedge fund manager Bill Ackman, whose Pershing Square Capital Management held a large long position in Valeant, was among the investors who sustained significant losses as the company's shares plummeted. The Financial Post reported that billions of dollars in market value were erased from Valeant's stock in the wake of the short-selling campaign and the subsequent revelations about the company's practices.

The Los Angeles Times covered the widening Valeant scandal in detail, noting how the controversy extended beyond Left's initial allegations to encompass broader questions about pharmaceutical pricing, corporate governance, and the relationship between Valeant and its network of specialty pharmacies. By March 2016, Left had described Valeant as "uninvestable," reinforcing his bearish thesis even as some investors speculated about a potential recovery in the stock. Fortune magazine chronicled the timeline of the Valeant scandal, which became one of the defining corporate controversies of the mid-2010s.

The Valeant case cemented Left's reputation as one of the most influential activist short sellers operating in the United States and demonstrated the capacity of independent research to challenge the practices of large publicly traded corporations.

Mallinckrodt Pharmaceuticals

In November 2015, shortly after the Valeant report, Left turned his attention to Mallinckrodt Pharmaceuticals, another company engaged in practices Left found questionable. Citron Research used its social media presence to draw attention to Mallinckrodt's H.P. Acthar Gel, a drug priced at approximately $35,000, placing the company's pricing practices back in the spotlight. Bloomberg reported on how a single tweet from Left's Citron Research account was sufficient to refocus public and investor attention on the pharmaceutical pricing controversy.

Legal Battles With Target Companies

Throughout his career, Left has been the subject of numerous lawsuits filed by companies targeted in Citron Research reports. These cases have tested the boundaries of free speech, securities regulation, and the rights of short sellers to publicly criticize publicly traded companies.

One notable case involved GTX Global Corp., which sued Left in response to critical research published by Citron. The case was documented by the Digital Media Law Project as an example of the legal risks faced by activist short sellers. Another case involved litigation arising from Left's reporting on companies involved in disaster rebuilding, as reported by The Times-Picayune of New Orleans.

Additional litigation involving Left has been documented in internet law case archives, reflecting the recurring pattern of companies attempting to use the legal system to silence critical research from short sellers.

Left has consistently maintained that he has never lost a lawsuit in the United States related to his research publications.

Federal Criminal Charges (2024–present)

In July 2024, federal prosecutors arrested and charged Left with multiple civil and criminal charges. The indictment alleged that Left had illegally manipulated the stock market by publishing research reports through Citron Research and then trading against the positions he had publicly recommended to investors. The charges represented a significant escalation of regulatory action against Left and raised broader questions about the legal boundaries of activist short selling.

Left's legal team filed motions to dismiss the criminal case, arguing that the government's charges were based on conduct that fell within the bounds of lawful market commentary and trading activity. In December 2025, a federal judge rejected Left's bid to dismiss the case, ruling that the prosecution could proceed to trial.

In November 2025, Institutional Investor reported that Left had petitioned the Securities and Exchange Commission (SEC) to define what constitutes illegal "scalping"—the practice of publicly recommending a stock position while privately trading in the opposite direction. Left's petition sought formal regulatory guidance that he argued would clarify the ambiguity surrounding the legality of his trading practices and potentially undermine the government's case against him.

In December 2025, Business Insider reported that Left had been using the artificial intelligence chatbot Claude to prepare for his upcoming criminal trial. The publication reviewed Left's conversations with the AI system, in which he discussed his legal strategy and concerns about the case. The report highlighted the unusual approach of a defendant in a major securities fraud case turning to AI for assistance in structuring his defense arguments.

As of February 2026, the criminal case remains pending, with Left facing a trial that is expected to become a landmark proceeding in the regulation of activist short selling in the United States.

Personal Life

Left resides in the United States. Limited publicly verified information is available regarding his personal and family life. Left has maintained a relatively low personal profile outside of his professional activities, with his public presence largely centered on his work at Citron Research and his media appearances discussing financial markets.

Recognition

Left's work as an activist short seller has attracted significant media attention and public recognition, both positive and negative. In 2017, The New York Times profiled Left under the headline "The Bounty Hunter of Wall Street," a characterization that reflected his reputation for pursuing companies he believed were engaged in fraud or were significantly overvalued.

Left has been a frequent guest on CNBC, Bloomberg Television, and other financial news programs, where he has discussed his research and his views on the stocks he has investigated. His Valeant Pharmaceuticals campaign, in particular, established him as one of the most recognized activist short sellers in the United States.

Bloomberg has featured Left's work on multiple occasions, including in connection with his research on Valeant, Mallinckrodt, and other companies. The Motley Fool's CAPS community has also documented instances where Citron Research's short-selling theses were vindicated by subsequent developments at the targeted companies.

Left's career has also generated controversy. His ban from Hong Kong markets, his early NFA sanction, and his federal criminal indictment in 2024 have all contributed to a polarized reputation. Supporters view him as an independent watchdog who has exposed genuine corporate fraud and overvaluation, while critics have questioned his methods and the alignment of his public research with his personal trading activity.

Legacy

Andrew Left's career at Citron Research has intersected with several of the most significant financial controversies of the 2010s and 2020s. His research on Valeant Pharmaceuticals contributed to the unraveling of a company that had become one of the most prominent and controversial firms in the pharmaceutical industry, and his report on Evergrande Group in 2012 preceded by nearly a decade the Chinese property developer's historic default and the broader crisis in China's real estate sector.

Left's work has also contributed to ongoing debates about the role of short sellers in financial markets. Advocates of short selling argue that researchers like Left serve a critical market function by identifying overvaluation and fraud that traditional analysts, who are often conflicted by their firms' investment banking relationships, may overlook. Critics contend that activist short sellers can manipulate markets by publishing negative reports designed to drive down stock prices for their own profit.

The federal criminal case against Left, pending as of early 2026, has the potential to establish important legal precedent regarding the boundaries between legitimate activist short selling and illegal market manipulation. The outcome of the trial is expected to be closely watched by short sellers, hedge fund managers, securities regulators, and legal scholars.

Left's use of social media and online publishing to disseminate financial research, beginning with the early days of StockLemon.com, also anticipated the broader democratization of investment research that has characterized the financial industry in the 21st century. Citron Research's model of publishing freely available, opinionated research online, rather than through traditional Wall Street channels, has been emulated by numerous other independent research operations.