A stock rout in Japan wiped out US$15 billion of SoftBank Group Corp’s value on Monday, after the company’s biggest single-day fall since founder Masayoshi Son took the company public in 1998.

The technology giant’s stock fell 19%, extending its decline for the September quarter so far to 38%, in line to be the biggest such drop since 2001. The plunge comes as Son prepares an investment blitz in AI and semiconductor technologies. The global market rout also threatens to hurt SoftBank’s Vision Fund unit, which holds investments in hundreds of technology startups.

“AI’s hype is fading now that there’s a greater focus on AI companies’ ability to deliver revenue and earnings,” Bloomberg Intelligence analysts Marvin Lo and Chris Muckensturm wrote in a note. “SoftBank’s AI investment strategy might help the company return to profitability, but it might not be smooth sailing with execution risk high.”

The Topix and Nikkei 225 Stock Average tumbled 12% Monday on a surge in the yen, tighter monetary policy and the deteriorating economic outlook in the US. SoftBank is scheduled to release its quarterly results Wednesday, when it’s expected to report a slim profit.

“The selloff is overdone,” said Kirk Boodry, an analyst at Astris Advisory. “The last time SoftBank Group traded like this was the capitulation trade when Covid fears swamped markets and the discount to net asset value was almost 70% at one point.” 

The discount has expanded to 57% today as markets account for higher volatility and risk for SoftBank investments, according to Boodry. The day’s stock declines are not wholly tech-related and reflect rising concerns over a stronger yen and geopolitical risks surrounding the Middle East, he added. 

  - Bloomberg