The Globe and Mail reports in its Thursday edition that Xanadu Quantum Technologies has been on a wild stock market ride since going public three weeks ago. The Globe's Sean Silcoff writes that the Toronto company, which had its Nasdaq trading debut on March 27, closing that day at $11.50 (all figures U.S.). It closed last Thursday at $7.65. Since then, the stock has been on an exponential tear, closing Wednesday at $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 Toronto Stock Exchange for a few minutes. That made Xanadu Canada's fifth-most valuable publicly traded technology company, with a market capitalization of $7.5-billion. Founder and chief executive officer Christian Weedbrook, who has 46.4 million multiple voting shares, is now a billionaire. Much of this week's gains happened after AI chip behemoth Nvidia 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.