Xanadu CEO Christian Weedbrook at the company’s headquarters in Toronto on March 25.Eduardo Lima/The Canadian Press
Xanadu Quantum Technologies Ltd.’s XNDU-T ferocious stock market rally hit a breaking point Thursday – five of them, to be exact.
Trading in the Toronto company was temporarily halted on the Toronto Stock Exchange four times Thursday by the Canadian Investment Regulatory Organization. The stock was up by more than 65 per cent at one point in the early afternoon to $57 a share.
The stock was halted a fifth time after the shares sold off sharply in late-afternoon trading from elevated levels.
CIRO cited the “single-stock circuit breaker” as the cause. CIRO implements this type of halt “to address rapid, significant and unexplained price movement in a particular security that calls into question whether there is a ‘fair and orderly market’ for that security,” its website states. CIRO also briefly halted trading once on Wednesday.
Xanadu began trading on March 27 on the TSX and Nasdaq after combining with a publicly listed special purpose acquisition company. After a strong trading debut on its first day, when it closed at $16.03 a share, the stock faded, ending last Thursday at $10.75 on the TSX.
Shares of newly public Xanadu take wild ride as Nvidia breakthrough boosts quantum sector
Since then, the stock has taken a quantum leap. It appreciated in value by 17.1 per cent last Friday, 28.2 per cent on Monday, 29 per cent on Tuesday and 70 per cent on Wednesday on the Nasdaq, which accounts for an overwhelming majority of the stock’s trading volume.
The stock ended Thursday up more than 29 per cent at $44.50 on the TSX and US$32.67 on the Nasdaq, giving it a market capitalization of US$9.7-billion, making Xanadu Canada’s fifth-most valuable publicly traded technology company. Investors with $1-billion-plus stakes at that level include founder and chief executive officer Christian Weedbrook; the company’s first institutional investor, the Ontario Municipal Employees Retirement System pension fund; and Toronto venture growth capital firm Georgian.
In total, Xanadu stock has appreciated by a cumulative 313 per cent on the TSX in the past five trading sessions.
Much of this week’s gains happened after chip behemoth Nvidia Corp. NVDA-Q said Tuesday that its new open-source family of artificial-intelligence models will enable researchers and businesses to speed up the performance and accuracy of the decoding process needed to correct errors that are part of the process of quantum computing operations. Reducing errors is a key challenge all quantum computer developers must solve before their machines can operate at full scale.
Nvidia’s news initially pushed up stocks of all quantum computer companies as tech stocks rose overall, but Xanadu’s continued rise Thursday was not mirrored by the rest of the sector, perhaps because the majority of its stock, held by Xanadu’s private investors and employees, is covered by a lockup agreement that doesn’t expire until September, meaning that only a minority of shares are available to trade.
“There’s an understandable exuberance for the business because if the technology pans out, it’s a game-changer,” said Michael Hyatt, an early Xanadu investor. “If quantum pans out to what we think it will be in the next few years, the stock is wildly undervalued.”
Quantum stocks have gyrated wildly in the past few years, making strong gains in late 2024 and through 2025 on the heels of a string of technical breakthroughs by developers of the machines, which harness the peculiar attributes of subatomic particles for their computing power. They subsequently sold off more recently as geopolitical uncertainty mounted and tech valuations declined broadly.
Quantum computing is still a speculative business; all machines in development are years from reaching their forecast potential. But when they do, they are expected to vastly outperform the world’s most powerful computers in several categories. That in theory should allow them to speed through sophisticated tasks such as complex economic forecasting, discovering advanced materials and pharmaceuticals – and, if used by bad actors, pick the cryptographic locks that protect global online systems.
There are several approaches to building quantum computers. Xanadu’s involves using light as its medium of calculation. That makes its system simpler and less costly than others to develop, as it dispenses with the need to keep its system ultracold, which is required for other systems. Xanadu’s quantum effects occur at room temperature.
Xanadu has emerged as one of the nascent sector’s leaders. It has published four papers in the journal Nature documenting its scientific breakthroughs. In 2025, it advanced to the second stage of an international competition held by the U.S. Defense Advanced Research Projects Agency that challenged quantum computer developers to prove their machines will work by 2033. Two other Canadian companies, Photonic Inc. and Nord Quantique Inc., are also in the running.