Gemalto said on Monday its initial investigations into a report that U.S. and British spies had hacked it systems showed its products were secure and it thus did not expect a significant financial prejudice.

Gemalto’s shares fell sharply on Friday after news website Intercept reported a hack by the U.S. National Security Agency (NSA) and Britain’s Government Communications Headquarters (GCHQ).

The hack into the world’s biggest maker of phone SIM cards allowed the spies to potentially monitor the calls, texts and emails of billions of mobile users around the world, the investigative news website reported.

Gemalto said it would communicate on the results of its investigations on Wednesday, Feb. 25 through a press release and a press conference that will be held in Paris at 0930 GMT.

Gemalto makes smart chips for mobile phones, bank cards and biometric passports and counts Verizon, AT&T Inc. and Vodafone among its 450 wireless network provider customers around the world.