Sony shares tumbled 13% on Wednesday (January 19).
That as investors weigh up a big new challenge from Microsoft.
The U.S. giant is buying game maker Activision Blizzard for $68.7 billion.
That will give it control of blockbuster games including the "Call of Duty" series.
The deal suggests Microsoft is bulking up on content as gaming moves from consoles to online platforms, including its own Game Pass service.
Wedbush Securities MD Michael Pachter:
"Sony are big losers because, you know, some of this content is not going to be a PlayStation in the future."
Sony has long been seen as the market leader in consoles.
It's also strengthened its list of in-house games, including hits like the Spider-Man franchise.
And the PlayStation is a major source of revenue for Activision, potentially complicating the Microsoft deal.
Michael Pachter again:
"It's an open question whether the regulators will allow Microsoft to exclude PlayStation from the mix. And that's the part that could be an impediment to the deal getting done there."
Long-term, both Sony and Microsoft have an eye on new rivals like Apple, Amazon and Facebook.
They all see games moving away from bulky consoles, to become a purely online experience.
The winner then will be the one with the best content, not the best hardware.