Sony Group Corp shares fell 13 percent in Tokyo yesterday, their biggest drop since October 2008, after PlayStation rival Microsoft Corp announced a US$69 billion deal to acquire games publisher Activision Blizzard Inc. The blockbuster acquisition escalates Microsoft’s spending spree to secure intellectual property assets for its Xbox Game Pass service, wiping US$20 billion off Sony’s valuation. The push to attract paying subscribers with an overwhelming portfolio of games challenges Sony’s traditional console business model that relies on high-profile exclusive titles and hardware sale...