Masayoshi Son Bets on Fusion for AI Power, SoftBank Doubles Down for Second Round

According to Monitoring, SoftBank founder Masayoshi Son predicts that by 2040, global data centers will require 3 terawatts of power.

In the short term, the majority of new electricity demand still relies on natural gas. Around 15 years from now, nuclear fusion may become a cheaper, cleaner, and safer alternative.

This is not just speculation. SoftBank Vision Fund II has continuously invested in the U.S. fusion energy company Helion, participating in its 2025 Series F and 2026 Series G funding rounds.

Helion's latest funding round of $465 million has brought its valuation to $15.5 billion. Fusion energy has not yet achieved commercialized power generation, and there remains significant uncertainty about whether it can scale up for large-scale power delivery on schedule.

In the face of skepticism about an AI bubble, Masayoshi Son has called it a "profoundly stupid question." He believes that the massive investments in data centers will ultimately pay off.