Once rejected Ken Griffin, now 35 years old and managing $20 billion, this "short-selling fanatic" makes Wall Street love and hate him!

Ask AI · How did his contrarian investment strategy develop from betting on Jaguar Land Rover?

In 2020, the young Hamza Lemssouguer received an invitation from hedge fund giant and Citadel founder Ken Griffin to run a multi-billion-dollar European credit fund. He declined.

Now, this 35-year-old Moroccan-born fund manager has established his own firm, Arini Capital, managing over $20 billion in credit hedge funds. According to data provider Hedge Fund Research, its growth rate since inception ranks first among emerging hedge fund managers.

Lemssouguer’s short bets have repeatedly gained an edge, earning both industry admiration and fear.

His short positions in software companies like ZipRecruiter and Unisys, initiated in Q3 2025, initially showed no results but later paid off as the “SaaS doomsday” panic swept through the debt markets. According to insiders, Arini’s flagship fund has an average annual return of about 15%, more than double the 7% average of the HFR Credit Hedge Fund Index.

However, Lemssouguer’s aggressive style has also made him many enemies. Competitors and bank traders criticize him for over-reliance on leverage, leading to significant performance swings — the flagship fund once experienced a monthly decline of 6%, and in 2024, it returned only 9%, partly because he persisted with short positions during most market uptrends. “He has a lot of ‘haters’,” said Rupak Ghose, an investment banker and financial industry commentator who has advised hedge funds.

“Look at our track record — whether markets go up or down, we can generate excess returns thanks to strong risk management,” Lemssouguer said in an interview at his Tudor estate in the outskirts of London, which has been in his family for 400 years. Inside, he lives with his wife, children, and 160 rare parrots. — A fund manager who neither drinks nor drives, and whose greatest hobby is raising parrots, is writing his own legend in the City of London in a rather unconventional way.

From Casablanca to Elite Academia: The Unconventional Growth Path

Lemssouguer was born into an ordinary family in Casablanca, Morocco. His father worked at the port, his mother was a teacher, and he has three siblings.

He was quiet and reserved from a young age, excelling in three areas: painting, raising parrots, and mathematics. His talent in math opened the door to France’s top elite university, École Polytechnique — regarded as the French equivalent of MIT combined with West Point.

In 2014, Lemssouguer joined Credit Suisse’s London office, taking his first step in his career.

He mastered American English by repeatedly watching American TV shows like “Friends” and “The Fresh Prince of Bel-Air.”

Thanks to his excellent bond trading skills, he quickly rose to become a top trader at Credit Suisse, managing about $100 million in proprietary funds by 2016.

Jaguar Land Rover Bet: Laying the Foundation for a Contrarian Style

In 2016, a pivotal battle established Lemssouguer’s personal style.

At that time, Jaguar Land Rover’s revenue was rising, and the market widely expected its credit rating to be upgraded. After visiting multiple dealerships, Lemssouguer discovered inventory was piling up, signaling a slowdown in sales. “I took a contrarian view,” he said.

He allocated about 10% of his portfolio to credit default swaps (CDS), betting that bond investors would turn bearish on the automaker, causing these positions to appreciate.

In 2017, Jaguar Land Rover’s sales data indeed declined, and this trade generated roughly five times the return for Credit Suisse. Since then, Lemssouguer has adopted a fixed pattern: deep data analysis, forming high-confidence judgments, and pushing positions to the limit.

He would celebrate each big win by playing his favorite rapper The Notorious B.I.G.’s music on the trading floor.

A former colleague recalled: “When I heard about Hamza’s performance in his first year, I thought ‘Anyone could get lucky once.’ When he continued to succeed in his second year, I thought ‘He’ll definitely blow up next year’ — but he never lost money.”

COVID-19 Turned Him Famous, Then He Declined Griffin’s Offer

In early 2020, as the COVID-19 pandemic spread, Lemssouguer launched a short-selling campaign against cash-strapped companies totaling about $1 billion, including car rental firm Europcar Mobility Group.

In Q1 2020, this strategy earned about $220 million in profit.

That same year, Citadel extended an olive branch, inviting him to run a European credit fund.

Lemssouguer initially accepted but then changed his mind — Credit Suisse agreed to help him set up an independent fund and retain his existing trading team.

However, just before the plan was to launch in early 2021, Credit Suisse’s hedge fund business suddenly collapsed, forcing him to seek new backing, ultimately securing support from large hedge fund Squarepoint Capital.

Arini Emerges: Assets Under Management Surged Over 15 Times in Two Years

In early 2022, Arini Capital was officially launched with $1.3 billion, focusing on highly leveraged companies, providing loans to some, buying or shorting their bonds, often with heavy positions.

But the start was rocky: the Russia-Ukraine war broke out, global interest rates soared, European corporate bond prices plunged, and the fund lost 15% from March to September that year. Lemssouguer later admitted that not having a dedicated risk hedging trader at launch was his biggest mistake.

Despite this, Arini ended the year with a 4% positive return.

Subsequently, Lemssouguer brought in trader Ardacan Celebi from Deutsche Bank — also a graduate of a top French math school. Celebi built what Arini calls the “risk mitigation engine,” using derivatives, bonds, ETFs, and other tools to absorb market shocks, allowing the fund to maintain an aggressive stance amid volatility.

“Maximum drawdown is what can force you out,” Celebi said.

Today, Arini’s team includes analysts and traders from Afghanistan, Turkey, Ukraine, and other countries working closely together.

After reaching $4 billion in assets, the fund closed to external investors. The firm is now heavily expanding its collateralized loan obligation (CLO) and private credit businesses — which, while charging lower fees than hedge funds, have larger growth potential. About 60% of its funds are from North America.

Controversy Over the Model: Can Centralized Collaboration Withstand Market Stress?

In terms of operational structure, Arini is very different from multi-strategy platforms like Citadel.

While Citadel’s various independent teams compete against each other, all of Arini’s funds share a single research team of 20 industry analysts, sharing information and coordinating judgments. Lemssouguer believes this allows the firm to capture investment opportunities more quickly.

Critics, however, point out potential risks: the holdings across funds could become highly correlated, and in a market upheaval, risks might concentrate and explode. Moreover, Arini’s “risk mitigation engine” has yet to face a long-term market downturn.

Facing these doubts, Lemssouguer remains true to his unconventional stance.

“Being young, and as an outsider and non-traditionalist, keeps me from being arrogant about the markets,” he said.