SoftBank Group shares extended their scorching rally to a second day, rising over 11% Friday, and building on momentum after Nvidia’s blockbuster earnings boosted AI-linked stocks.

The company’s shares had closed 20% higher Thursday, adding over $35 billion to its market cap.

Softbank rally is also being powered by a sharp rise in Arm Holdings, in which the Japanese company holds a majority stake. Arm shares advanced over 16% overnight, after gaining more than 15% in the prior session.

“SoftBank Group’s share price is simply reflecting the moves of some of its stake holdings, including Arm, whose share price has been surging, and OpenAI which may file for an IPO in the coming weeks,” UBP’s senior equity advisor Vey Sern Ling told CNBC.

However, Ling cautioned that investors typically apply a discount to holding companies such as SoftBank because shareholders do not always fully benefit from the value of the underlying assets they own.

“Net asset value (NAV) or sum-of-the-parts (SOTP) valuations usually warrant a significant discount or cautiousness as shareholders of the holding company rarely receive the full value of the underlying assets,” he said.

SoftBank has invested heavily into the ChatGPT maker, and the IPO set to unlock value for SoftBank, even as analysts suggest it might be limited. The company has emerged as one of OpenAI’s largest backers, investing more than $30 billion into OpenAI and booking roughly $45 billion in related gains in the fiscal year ended March.

Nvidia recent results have reinforced optimism around continued spending on AI infrastructure and data centers. Arm Holdings’ chip designs are used in AI servers and data centers powered by Nvidia systems.

“For investors, SoftBank is a compelling way to gain exposure to the data center CPU boom, which is the fastest growing segment in AI semis, and early exposure to the OpenAI IPO,” said Rolf Bulk, head of semiconductor and infrastructure at Futurum Group.