XTB shares fell more than 8% today (Wednesday) to close below 100 zlotys, the Warsaw-listed broker's sharpest single-session decline in months and a striking reversal of the rally that carried the stock to a record 114 zlotys in April.

Trading volume ran more than 50% above the three-month daily average, signaling institutional positioning rather than retail noise.

A Sell-Off Without an Obvious Catalyst

XTB did not publish an ESPI disclosure on Wednesday. Poland's Financial Supervision Authority did not announce a new investigation, sanction, or rule. No analyst note circulated that would account for an 8% repricing of one of the Warsaw exchange Exchange An exchange is known as a marketplace that supports the trading of derivatives, commodities, securities, and other financial instruments.Generally, an exchange is accessible through a digital platform or sometimes at a tangible address where investors organize to perform trading. Among the chief responsibilities of an exchange would be to uphold honest and fair-trading practices. These are instrumental in making sure that the distribution of supported security rates on that exchange are effectiv An exchange is known as a marketplace that supports the trading of derivatives, commodities, securities, and other financial instruments.Generally, an exchange is accessible through a digital platform or sometimes at a tangible address where investors organize to perform trading. Among the chief responsibilities of an exchange would be to uphold honest and fair-trading practices. These are instrumental in making sure that the distribution of supported security rates on that exchange are effectiv Read this Term's best-performing stocks of 2026.

Polish financial press has connected the slide to renewed unease about the KNF's ongoing review of how Contracts for Difference are sold to retail clients. That review, and the regulator's thinking around it, has been public knowledge for weeks.

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“Many investors appear to have been spooked by media reports - which, in my view, were somewhat overinterpreted - suggesting that the KNF intends to take a tougher stance on CFDs,” Arkadiusz Jóżwiak, the Editor-in-Chief at Comparic.pl, commented for FinanceMagnates.com “The old market adage is to buy the rumor. This time, however, we witnessed investors selling it.”

As FinanceMagnates.com reported earlier this month, KNF vice-chairman Dariusz Adamski said the "capital market cannot function like gambling" and confirmed the regulator was widening its CFD review.

What is unclear is why the same regulatory thesis the market discounted two weeks ago would today drive XTB shares more than 8% lower on outsized volume.

A Different Reaction From Six Weeks Ago

The contrast with April makes the move more conspicuous. On April 13, KNF imposed a 20 million zloty ($5.5 million) fine on XTB over MiFID II MiFID II MiFID II stands for the Markets in Financial Instruments Directive, and is the second iteration of a sweeping directive. As such it is known as MiFID II. The original Markets in Financial Instruments Directive (MiFID) became effective in November 2007. It was intended as the foundation of the EU’s Financial Services Action Plan, a comprehensive project to create a single European market in financial services. MiFID is intended to create a level playing field for firms to compete in the EU’s fina MiFID II stands for the Markets in Financial Instruments Directive, and is the second iteration of a sweeping directive. As such it is known as MiFID II. The original Markets in Financial Instruments Directive (MiFID) became effective in November 2007. It was intended as the foundation of the EU’s Financial Services Action Plan, a comprehensive project to create a single European market in financial services. MiFID is intended to create a level playing field for firms to compete in the EU’s fina Read this Term breaches in client onboarding between 2022 and 2023. The stock rose the following day and kept climbing, hitting an all-time high of around 114 zlotys just over a week later. A confirmed financial penalty did not dent the rally.

Six weeks later, with no new fine, no new XTB filing, and no fresh regulator action, the same stock has given back roughly 11% of its value from the April peak in a single day.

Broader Regulatory Pressure on CFDs Is Building Across Europe

The Polish regulator is not acting in isolation. The European Securities and Markets Authority has spent more than two years tightening supervisory expectations around retail leveraged products, and earlier this year acknowledged that MiFID II rules had become too complex for many ordinary investors, while continuing to scrutinize CFD providers' marketing and product design.

In February, ESMA also confirmed that perpetual futures meeting the CFD definition fall under the same retail restrictions as traditional CFDs, closing a workaround several crypto-linked brokers had been testing.

Spain's CNMV imposed sweeping curbs on CFD advertising in 2023, and Cyprus's CySEC has tightened oversight of retail-facing client acquisition for the same products.

Within that landscape, KNF has emerged as one of the more active CFD supervisors in the EU. Its widened review puts the Polish market on a similar trajectory to the gradual tightening seen in France, Spain, and the Netherlands over the past several years.

CFDs Still Power a Business That Sells Stocks and ETFs

The reason regulatory chatter, even without a fresh development, can move XTB shares this much is the broker's revenue mix. Although XTB markets equities, exchange-traded funds, and investor education to Polish retail clients alongside its CFD offering, leveraged contracts remain by far the largest profit driver.

Arnaout has acknowledged this directly, telling Polish media that "around 95%, or maybe even more, of revenue is generated from CFD instruments." He has framed diversification, including spot crypto and options, as a multi-year project rather than a near-term offset.

That dependence is why strong fundamentals failed to cushion Wednesday's reaction. XTB's first-quarter 2026 results showed net profit of 535 million zlotys, up 176% year over year, on operating income of 1.09 billion zlotys and 370,000 new clients added in a single quarter.

Noble Securities analysts have flagged a full-year 2026 net profit run-rate of around 1 billion zlotys, contingent on the broker maintaining current monetization rates. None of that protected the share price on Wednesday.

What Investors Will Watch Next

Without an official trigger to anchor the move, the next reference points are external. KNF has not yet published concrete proposals on new leverage caps, marketing restrictions, or suitability-test changes, nor a timeline for public consultation.

Whether any future measures will apply only to Poland or extend to XTB's FCA-regulated and CySEC-regulated units is also unclear. Sell-side analysts covering the broker may issue revision notes in the coming days as they recalibrate regulatory risk into existing models targeting a billion-zloty annual profit.

For now the stock trades roughly 22% above its 52-week low of 61.86 zlotys but about 11% below the April record, leaving room for further repricing if the regulatory outlook hardens or if whatever drove Wednesday's volume returns.