Toronto-based Xanadu rings the opening bell at the Nasdaq in New York City on March 27, marking its public debut and dual listing on the Nasdaq and the Toronto Stock Exchange.Supplied
Xanadu Quantum Technologies Ltd. XNDU-T has been on a wild stock market ride since going public three weeks ago.
The Toronto company, which went public by merging with a Nasdaq-listed special-purpose acquisition company, saw its share price slide after its strong trading debut on March 27. It closed that day at US$11.50 but ended last Thursday at US$7.65.
Since then, the stock has been on an exponential tear, appreciating in value by increasingly higher double-digit percentages each day. The stock closed up 17.1 per cent last Friday, 28.2 per cent on Monday, 29 per cent on Tuesday and 70 per cent on Wednesday, ending at US$25.18. Xanadu, which is also listed on the Toronto Stock Exchange, appreciated so rapidly late Wednesday morning that it triggered a temporary trading halt on the Canadian exchange for a few minutes.
That made Xanadu Canada’s fifth-most valuable publicly traded technology company, with a market capitalization of US$7.5-billion. Founder and chief executive officer Christian Weedbrook, who has 46.4 million multiple voting shares, is now a billionaire, though he has said he doesn’t pay much attention to the stock price.
Much of this week’s gains happened after chip behemoth Nvidia Corp. said Tuesday that its new open-source family of artificial intelligence models, called Ising, 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 pushed up stocks of all quantum computer companies, including B.C.-founded D-Wave Quantum Inc.
Other Xanadu backers are sitting on paper windfalls. The Ontario Municipal Employees Retirement System pension fund – one of the first investors in Xanadu and an early backer of Shopify Inc. and Constellation Software Inc. – owns 40.2 million shares of Xanadu, worth US$1-billion as of Wednesday. Toronto venture capital firm Georgian has 29.7 million shares, the vast majority of which are held by its Fund IV, which raised US$550-million in 2018. If Georgian could cash in at Wednesday’s price, it would be a “fund-maker,” or an exit that returns the entire fund, a rare achievement in venture capital.
That’s not something Georgian or other early Xanadu backers can take to the bank; they are subject to a 180-day lockup that lifts in September.
Xanadu founder and CEO Christian Weedbrook at the company’s headquarters in Toronto on March 25.Eduardo Lima/The Canadian Press
Plus, quantum stocks have gyrated wildly. They made 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. Quantum stocks sold off recently as geopolitical uncertainty mounted and the 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, as 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.
Editor’s note: A previous version of this article incorrectly said Xanadu's stock on Thursday appreciated by 70 percent, at one point triggering a temporary trading halt. That happened on Wednesday.