SoftBank's investment is certainly driven by financial returns—Nvidia's market capitalization, in particular, has grown significantly in recent years—but it's likely also driven by a desire to gain greater influence over the Californian company led by Jensen Huang. Masayoshi Son, SoftBank's founder and board member, also wants to convince Taiwanese company TSMC to participate in a $1 trillion project to create an artificial intelligence manufacturing hub in the U.S. state of Arizona.