10 Billionaires Who Built Fortunes Through Borderline Illegal Tactics

Making a billion dollars is difficult; keeping it without cutting corners is even harder. While many fortunes are built on innovation, hard work, or inheritance, a number of high-profile individuals made headlines for operating in legal gray areas—dodging rules, exploiting loopholes, or testing the limits of what’s considered lawful.

Allen Stanford — Built an $8 Billion Ponzi Empire in a Tropical Suit

Allen Stanford cultivated the image of a suave financial guru hosting meetings at island resorts, but beneath the polished exterior his firm, Stanford Financial Group, operated one of the largest Ponzi schemes in U.S. history. Over the course of its operation the company handled billions of dollars and attracted nearly 18,000 investors before regulators exposed the fraud.

Elizabeth Holmes — Raised Millions on a Blood Test That Didn’t Work

Elizabeth Holmes left college to found Theranos and promised a breakthrough: accurate lab results from a single drop of blood. Despite high-profile endorsements and a valuation that climbed into the billions, internal staff reported that the technology was unreliable. Holmes continued to raise funds and present optimistic claims while the company’s testing capabilities remained problematic.

Raj Rajaratnam — Turned Insider Tips Into a Billion-Dollar Hedge Fund

Raj Rajaratnam founded the Galleon Group and earned significant returns through a network of contacts. Much of that success was later attributed to trading on confidential information obtained from executives, consultants, and associates. Investigations revealed a wide-ranging insider trading scheme that shook Wall Street.

Vijay Mallya — Used Glamour and Debt to Fund a Lifestyle That Flew Too High

Known as the “King of Good Times,” Vijay Mallya built a public persona around airlines, Formula 1 sponsorships, and lavish parties. However, his companies accumulated massive debts—reportedly more than $1.3 billion in unpaid loans—and allegations of financial mismanagement and misreported assets followed. Facing legal action, he left India and his affairs became the subject of lengthy cross-border proceedings.

Joseph Lau — Bought a $48 Million Diamond While Dodging a Bribery Case

Hong Kong businessman Joseph Lau gained attention for extravagant purchases, including an exceptionally expensive pink diamond reportedly bought for his young daughter. At the same time, he was implicated in bribery allegations tied to land deals in Macau. Legal action and accusations complicated his public image as he continued to manage businesses internationally.

Michael Milken — Made Fortune With Junk Bonds Then Paid a Hefty Price

Michael Milken helped change corporate finance by popularizing high-yield, so-called “junk” bonds, fueling buyouts and growth in multiple industries. Later investigations into securities violations and alleged market manipulation resulted in substantial fines and convictions. In subsequent years Milken shifted toward philanthropy and public health initiatives.

Thomas Kwok — Gained Real Estate Intel by Paying Off a Top Official

As co-chair of a major Asian property developer, Thomas Kwok played a central role in shaping parts of Hong Kong’s skyline. In 2014 he was convicted of offering payments to a senior official in exchange for confidential information about land deals. He served a prison sentence and later returned to the family’s wider property interests.

Eike Batista — Hyped Up Oil and Mining Deals Before It All Crashed

Eike Batista once publicly declared ambitions to become the world’s richest person as his oil and mining ventures soared in value. His rise was dramatic, and so was his fall, as investigations and market realities revealed overstated asset values and undisclosed liabilities that decimated his fortune.

Donald Trump — Used Loopholes to Shrink Tax Bill to Just $750

Before and during his political career, Donald Trump’s finances drew scrutiny. Reporting showed that for certain years he paid a very small amount in federal income tax—figures that prompted debate about the use of deductions, business losses, and accounting strategies to minimize tax liability. The disclosures fueled extensive public and legal discussion about tax practices.

Silvio Berlusconi — Mixed Media Money With Political Power (and Legal Headaches)

Silvio Berlusconi combined control of a major media group with political leadership and business investments. His career featured numerous legal entanglements, including tax disputes and allegations of corruption, and his business and political roles often overlapped in ways that attracted scrutiny and controversy.

Gupta Family — Turned Friendship With a President Into Billion-Dollar Influence

The Gupta family emigrated to South Africa and developed close ties with political leaders, most notably former president Jacob Zuma. Their influence extended into government appointments and major state contracts, spawning allegations of “state capture,” where private interests were accused of exerting undue control over public institutions and procurement.

Khadem al-Qubaisi — Threw Lavish Parties With Money From a Missing Billion

Khadem al-Qubaisi has been linked to spending associated with the 1MDB scandal, one of the most complex financial investigations in recent years. Allegations of missing funds corresponded with high-end purchases and extravagant events, prompting deeper inquiries into the sources and movement of large sums connected to state-backed entities.

Rupert Murdoch — Built a Media Empire That Got Tangled in Phone Hacking

Rupert Murdoch built one of the world’s largest media empires, but it was not without scandal. In 2011 revelations surfaced that some tabloids within his organizations had engaged in phone hacking and other invasive practices, leading to public outrage, legal action, resignations, and regulatory scrutiny that dented aspects of his company’s reputation.

Beny Steinmetz — Won Diamond Rights With Bribes and Lost Credibility in Court

Beny Steinmetz amassed wealth through international mining ventures, but key deals—especially in Guinea—prompted allegations of bribery tied to the award of mining rights. Investigations and court cases in multiple countries raised questions about how those contracts were obtained and the legality of the practices involved.

Ihor Kolomoyskyy — Bought U.S. Real Estate Using Hidden Funds, Say Investigators

Ukrainian businessman Ihor Kolomoyskyy has been involved in energy, media, and banking sectors, and he served as a regional governor during a turbulent period. U.S. authorities and journalists later scrutinized certain real estate purchases in cities such as Cleveland and Miami, suggesting complex funding arrangements and prompting questions about the origins of some acquisitions.