In the meantime, the surge has propelled Tera’s founder into the ranks of the richest people in Turkey. Emre Tezmen, a 53-year-old former financial analyst, founded the firm 20 years ago and owns a 32% stake that is now worth $1.4 billion. In an interview at Tera’s headquarters in Istanbul, he rejected any criticism of the firm’s strategy.

"Everything we do here is in line with the regulations," Tezmen said. "We haven't done anything that hasn't been done in global markets."

The frenzy around the firm began picking up steam in July last year, when it made the Tera Portfoy First Mutual Fund available to retail investors. The fund quickly drew an ardent following on social media. Regulatory filings show that at one point in 2023 the fund had 99% of its assets in a single stock — shares of its own parent, Tera. The fund bought shares in publicly traded Tera subsidiaries, and used borrowed money to buy more shares, filings show. And it invested in companies that Tera's brokerage unit had helped take public yet which had relatively few shares available for trading, known in finance as a small “free float.”Tera classifies the $2.7 billion fund as a high-risk investment. “It is designed for qualified investors with a medium- to long-term investment perspective, who can tolerate market fluctuations and are suitable for a high risk level,’’ according to the fund’s website. One of the most eye-popping examples of the Tera strategy: a finance company called Destek Finans Faktoring AS. Bankers for Tera took the company public in 2025 and Tera’s fund accumulated a stake that reached 26% of assets under management. The stock has surged more than 4,700% since the IPO at 46.98 liras a share, making Destek the third-largest company on the Borsa Istanbul, with an $18.8 billion market value. The Tera fund’s stake now accounts for 18% of the free float. A representative for Destek Finans said in an email that the stock’s performance is driven “by free market principles and the company doesn’t have any interference.”

Another Tera-owned stock that saw relatively extreme moves was mining company Visne Madencilik Uretim Sanayi ve Ticaret AS. In February 2025, Tera's brokerage arranged a small IPO for Visne that put just 21% of the company's outstanding stock in public hands.

The stock immediately began to soar and by the end of July was up by more than 2,100%. That same month, Tera's main fund and brokerage sold the Visne shares they had purchased in the IPO, filings show. The next month, the stock crashed. It lost 75% in August alone and is now down 89% from its peak. A Visne representative declined to comment.

Tera’s trading of Visne ran afoul of regulators. In October, the Capital Markets Board fined two of the firm’s fund managers 8.9 million liras ($199,000) each over transactions involving the stock. They created “misleading perception on the price, supply and demand” for the shares, the regulator said, without elaborating. Tera didn’t reply to a request for comment on the fines.

Such wild stock moves are more than just a quirk. They’re not uncommon in some less-developed markets and can have real repercussions, potentially calling into question a market’s integrity and driving away big investors.

To Kamil Dimmich at North of South Capital LLP in London, the moves are similar to what’s played out in another emerging market, Indonesia, in recent years. The country has experienced a boom in speculative retail trading with unexplained stock swings of more than 1,000% becoming increasingly common. Some of the biggest gains have been in companies that have low trading volumes and concentrated ownership.

That speculative excess has drawn concern from index compiler MSCI Inc., which warned about the Indonesian market's investability and a potential downgrade to frontier-market status. The warning sparked a plunge that has wiped 19% off the value of Southeast Asia's biggest equity market. Indonesia’s exchange operator said this week it will remove companies with a high concentration of shareholders from some key indexes as a part of market reforms.

The Tera-related stock moves reflect "nonsensical squeezes and valuations" fueled by a small free float and a "wild retail shareholder base," said Dimmich, who helps oversee more than $8 billion at the emerging markets fund.

Officials in Turkey recently acknowledged concerns about unusual market moves, without mentioning Tera. Treasury and Finance Minister Mehmet Simsek said in November that authorities were aware of manipulation risks in some investment funds and would strengthen the regulatory framework. Capital Markets Board Chairman Omer Gonul has also pledged tougher penalties for market abuse.

Tera used massive amounts of borrowing last year, filings show. The brokerage’s borrowing soared to 59.8 billion liras, or about $1.3 billion, at the end of 2025, up from 132 million liras, or about $2.9 million, a year earlier, according to the company’s earnings report. Securities given as collateral climbed to 32.6 billion liras in 2025, up from 121.3 million in the previous year.

Tezmen said Tera has now reduced its use of such loans, without elaborating further on the figures. Using short-term borrowing can make sense when interest rates are falling, and it’s a strategy that many banks use, he said.

Asked about concerns over holding stakes in companies with little free float while using short-term debt, Tezmen dismissed the idea that stock prices can be controlled. He declined to comment on the valuation of Destek Finans or other companies that Tera has taken public or invested in.

“You cannot control anything 100% in a market,” he said. “If that were the case, prices would only go up. There’s no way you can control the market.”

Most Read from Bloomberg Businessweek

• ‘I Have Half of MAGA’: The Republican Challenging Trump From Within

• AI Startup Has Helped Reverse Thousands of Denied Health Insurance Claims

• United’s CEO Is Here to Buy Your Struggling Airline

• QVC Lost the Home Shoppers to Social Media Influencers