He Turned Down Ken Griffin to Run His Own Fund. That Was $20 Billion Ago.

April 4, 2026 - 12:44

In the high-stakes world of finance, a 36-year-old trader is making waves from his base in London. Hamza Lemssouguer, founder of the hedge fund Arini, has built a formidable reputation and a multi-billion dollar fortune not by following the crowd, but by boldly betting against it. His story is marked by a pivotal early decision: turning down a lucrative offer from billionaire Ken Griffin's Citadel to forge his own path.

Lemssouguer's strategy centers on sophisticated short-selling, a practice of profiting from falling stock prices. While many funds chase rising markets, Arini has consistently identified overvalued companies and macroeconomic trends poised for a downturn. This contrarian approach, executed with rigorous research and disciplined risk management, has delivered extraordinary returns for his investors, with the fund's assets reportedly swelling by billions since its inception.

His success challenges the traditional image of a City of London financier, proving that deep analytical skill and conviction can trump decades of experience. Lemssouguer's rise underscores a shift in the industry, where a new generation of data-driven, specialized traders can achieve outsized success by mastering niche strategies. As markets remain volatile, all eyes are on this young manager and his next major move.