Turkish investment funds are reportedly urging authorities to crack down on unusual trading activity that has put Turkey’s stock exchange at risk of exclusion from major equity benchmarks.

The activity has sent some Borsa Istanbul stock prices soaring, with some traders alleging flagrant manipulation, according to a Bloomberg report.

Money managers overseeing some of the country’s largest mutual funds want tougher measures than those proposed by the Capital Markets Board (SPK) to combat the malpractice, five fund managers told the news service. These include harsher penalties and curbing hedge fund activity in some instruments.

IntelliNews has long covered the “robberies” seen on Borsa Istanbul, dubbing the exchange “Casino Istanbul”.

SPK was yet to respond to the calls for action, according to sources spoken to for the Bloomberg article, most of whom made comments on condition of anonymity, citing the sensitivity of the matter. The regulator shared draft proposals for change with investors in February. It declined to comment when contacted by Bloomberg.

Concerns relate to meteoric share price gains seen in recent years, surpassing 1,000% in some instances, many of them in small and illiquid stocks. Also under scrutiny are certain strategies used by funds whose holdings deliver unusually high returns over a short period.

While the benchmark BIST 100 index was among the world’s top performers during the first half of 2026, its gains were driven by extraordinary rallies in just a handful of names.

The swings drew warnings from index providers MSCI Inc and S&P Dow Jones Indices LLC, which said that without more shareholder transparency, Turkey could be ejected from their equity benchmarks tracking emerging markets. It could instead be re-classified as a frontier market, a move that’s likely to sharply reduce investment flows from overseas.

The total market value of companies on MSCI’s emerging-markets index is $29.4 trillion, a value that is more than 40 times larger than the frontier markets index figure of just over $700bn, according to data compiled by Bloomberg.

SPK needs to act against the “blatant manipulation currently taking place,” Murat Gulkan, chief executive officer of OMG Capital Advisors, who also highlighted risks to local retail investors, was quoted as saying.

Some local funds with astronomical returns have gained cult followings among small-time traders.

“The regulator’s paramount responsibility is to maintain the public’s trust in the financial system,” Gulkan was further reported as saying.

Another Istanbul-based investor, who spoke on condition of anonymity, was reported as stating that they were most concerned by the unusually high and persistent fund returns via what they described as extensively manipulated stock prices, which then attracts thousands of additional investors into those funds.