The Globe and Mail reports in its Friday edition that Xanadu Quantum Technologies' ferocious stock market rally literally hit the breaking point Thursday. The Globe's Sean Silcoff writes that 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." 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. Since then, the stock has taken a quantum leap. The stock ended Thursday up more than 29 per cent at $44.50 on the TSX and $32.67 (U.S.) on Nasdaq.