D-Wave Quantum Inc. (QBTS) experienced a significant 24-hour plunge of 5.06% during the overnight session. The quantum computing stock's sharp decline came amid heightened investor scrutiny following news of substantial insider selling activity.

The stock's downward movement was primarily driven by the disclosure that the company's Chief Financial Officer, John M. Markovich, disposed of 328,752 common shares worth approximately $9.11 million. According to regulatory filings, Markovich exercised stock options at prices between $0.85 and $0.92 per share before immediately selling the shares at a weighted average price of $27.70 on May 22, 2026.

Such large-scale insider disposals often signal to the market that company executives may be taking profits or reducing their exposure, which can create selling pressure and lead to negative sentiment among investors. The timing and magnitude of this transaction appear to have contributed to the stock's significant decline in the overnight trading session.