Shares of IonQ (IONQ 9.66%) are down 21.2% this week as of Thursday's close, according to data provided by S&P Global Market Intelligence, driven by a combination of broader-market weakness and concerns over the departure of a key executive.

On the former, it certainly didn't help that the broader markets turned lower in recent days. The S&P 500 Index and Nasdaq Composite have each pulled back more than 3% this week as of this writing, serving as a headwind for richly valued growth stocks like IonQ.

Why IonQ's co-founder is leaving

Still, IonQ's decline this week accelerated on Tuesday when the quantum computing leader announced the departure of company co-founder and Chief Science Officer Dr. Chris Monroe. As Gilhuly Family Distinguished Presidential Professor of Physics and Electrical Computer Engineering at Duke University, Dr. Monroe is returning to his previous academic, research, and policy pursuits.

"Under his support and leadership, IonQ was granted exclusive ion trap intellectual property licenses from the University of Maryland and Duke University -- two distinguished research universities pushing the frontiers of quantum computing," added IonQ CEO Peter Chapman. "Chris has also helped guide the company to build scalable quantum computers that will drive commercial advantage."

Is IonQ stock a buy now?

While it's hardly surprising to see the market lament the loss of a key contributor to IonQ's quantum computing efforts, the company should fare just fine in his absence. "It has been a privilege to work alongside so many exceptionally talented engineers and scientists," added Dr. Monroe. "We have brought forward several first-in-class quantum technologies, culminating in a clear roadmap that is poised to drive commercial advantage in the future."

Indeed, IonQ only just announced a new $25.5 million quantum deal with the U.S. Air Force Research Lab last month. Earlier this week, the company also revealed it's now offering 24/7 access to its cloud-accessible quantum systems, IonQ Harmony and IonQ Aria, based on customer demand.

IonQ is slated to announce third-quarter 2023 results in roughly two weeks on Nov. 8, 2023. If it can continue translating its quantum industry leadership to quantifiable financial outperformance, I think this week's pullback could prove to be a compelling buying opportunity for patient, long-term investors.