Defense contractor L3Harris Technologies made a surprise change at the top, which unnerved investors on Monday.

L3Harris announced that CEO Christopher Kubasik stepped down after the company "became aware of certain conduct by Kubasik that was not consistent with the values of the Company as outlined in its Code of Conduct," according to a news release. "This conduct was unrelated to the Company's financial reporting, controls, customer relationships or operational performance."

L3Harris didn't immediately respond to a request for additional details.

Shares were down 3.2% at $282.54, while the S&P 500 was off 0.1%.

Now, Sam Mehta is the CEO. He joined the company in 2023 as president of the then-communication systems segment.

"I am honored by the opportunity to serve as President and CEO of L3Harris," said Mehta in a news release. "Today, L3Harris has a portfolio purpose-built for the future of warfare, and we are well-positioned to continue executing our focused growth strategy as The Trusted Disruptor."

Kubasik joined L3 Technologies in 2015 and led that company thorough its 2019 merger with Harris. He became CEO of the combined company in June 2021, and led the company through its 2023 acquisition of Aerojet Rocketdyne.

L3 shares were about $215 when Kubasik assumed the CEO title. Coming into Monday trading, they were up about 35% since then, trailing the S&P 500 by roughly 45 percentage points.

Shares, however, were essentially keeping up with the market until early March, when the Iran War started. The fighting, counterintuitively, helped catalyze a selloff in defense stocks that sent L3Harris stock off almost 20%. One issue affecting sentiment: Investors are worried that defense spending could slow if Democrats retake the House in the 2026 midterm elections.

It has "not escaped investors' attention that L3 Harris Technolgies' [stock] has underperformed its U.S. defense peers under Kubasik's leadership," wrote Vertical Research Partners analyst Rob Stallard on Monday.

He says L3Harris shares have underperformed peers by about 45 percentage points over the past five years.

"We have high regard for Sam Mehta, who in our experience has been an effective manager and a good communicator," he wrote. "He may be a catalyst for closing [the stock's] performance gap."

That might be the case eventually. Still, shares were lower on Monday. Investors don't like unexpected changes or turmoil at the top of an organization.