Shares of Booz Allen Hamilton moved sharply lower after The New York Times reported that Harold Thomas Martin, one of the firm's National Security Agency contractors, had been arrested for possible theft of classified computer code.
The stock was up as much as 0.8 percent before the report, but fell sharply after the news. The shares closed down 3.78 percent on Wednesday.
Former NSA contractor Edward Snowden also worked for the firm.
Booz Allen issued the following statement in a Wednesday filing:
"When Booz Allen learned of the arrest of one of its employees by the FBI, we immediately reached out to the authorities to offer our total cooperation in their investigation, and we fired the employee. We continue to cooperate fully with the government on its investigation into this serious matter. There have been no material changes to our client engagements as a result of this matter. Booz Allen is a 102-year-old company, and the alleged conduct does not reflect our core values. Thousands of our employees support critical client missions with dedication and excellence each day. Their professionalism, values and ethics are what define our firm."
With Wednesday's losses, the stock is down 1.75 percent so far this year.