TOKYO: SoftBank Group Corp has built a stake worth around US$1.2 billion (RM5 billion) in e-commerce firm Amazon, regulatory filings showed today, as the tech conglomerate expands its investing activities beyond its recent focus on unlisted startups.

Chief executive Masayoshi Son last week announced a new investment management subsidiary that would park excess cash from a massive asset sale programme in liquid stocks. SoftBank has spent around $10 billion buying shares.

In addition to Amazon, the group has built stakes in Netflix Inc, Tesla Inc, Microsoft Corp and Alphabet Inc, filings showed.

SoftBank also disclosed a stake in chip supplier Nvidia Corp worth around US$220 million based on Friday's closing price. It exited its stake in the firm last year. SoftBank is currently in talks with Nvidia over a possible sale of chip designer Arm, media have reported.

The group is pivoting towards investing outside the US$100 billion Vision Fund with its focus on unlisted, late stage startups. The fund has buffeted the group's earnings as the value of its holdings have fallen below acquisition price.

The value of many of the listed shares is rising, driven by a tech stock rally, with Tesla's shares up more than 60% since the end of June. Son has dropped operating profit as a measure of his group's performance, saying the value of the assets is a better yardstick.

SoftBank also disclosed stakes in Chinese video sites Bilibili Inc and iQIYI Inc. iQIYI is currently being probed by the US Securities and Exchange Commission.

In another development, Amazon.com Inc is in preliminary talks to invest in US cloud services provider Rackspace Technology Inc, people familiar with the discussion said.

The deal would involve Amazon acquiring a minority stake in Rackspace, the sources said.

Rackspace helps companies migrate their data to Amazon Web Services, and the investment would strengthen the ties between the two companies. Rackspace also migrates companies to Alphabet Inc's Google Cloud, Microsoft Corp's Azure and VMware Inc.

There is no certainty that Amazon and Rackspace, which is majority owned by private equity firm Apollo Global Management Inc, will agree a deal, the sources said. If there is one, it could take one to two months to negotiate it, the sourced added, asking anonymity because the matter is confidential.

Rackspace and Apollo declined to comment, while Amazon did not respond to a request for comment.

Rackspace leases server space and helps corporations store and access data in the cloud. Rackspace shares soared as much as 17% on the news. – Reuters