Microsoft’s announcement of an Activision Blizzard acquisition has affected Sony shares as they fell almost 13%. It resulted in the Japanese company losing $20 billion off its market value.

On January 19, Sony saw the biggest share drop since October 2008, according to Bloomberg. The price fell from ¥14,230 ($124.25) per share on Tuesday to ¥12,410 ($108.36) today.

“Sony will struggle to match Microsoft in terms of money it can spend to buy popular game IP,” Morningstar Research analyst Kazunori Ito said. “Falling shares illustrate investors are worried that Sony may not be able to keep winning if indeed the industry shifts away from the hardware-based model.”

Although there is still no confirmation about Activision Blizzard IPs becoming Xbox and PC exclusives, Sony will definitely have to respond to this deal or make some changes to its business model, which is built around the AAA platform exclusives, in the future.

Microsoft announced its plans to acquire the Call of Duty and Diablo maker for $68.7 billion on January 18. The deal must be approved by regulators and shareholders. If it’s not, Microsoft will have to pay Activision a $3 billion fee.