The telecoms-firm-turned-investment giant posted a net loss of 397.9 billion yen ($3.5 billion) in July-September, the first since January-March 2020, dragging first-half net profit down more than 80 percent on-year.

SoftBank Group has poured money into some of the tech world's biggest names and hottest new ventures, from AI to biotech, through its $100-billion Vision Fund.

But those investments have proved tumultuous, with CEO Masayoshi Son saying Monday the firm was "in the middle of a blizzard".

In total, SoftBank said its loss on investments during the quarter amounted to 1.66 trillion yen, including those incurred by its Vision Fund operations.

"We're not proud of that," Son said of the first-half results. "Our most important indicator, the net asset value, has decreased by six trillion yen. Just in three months. This is a big deal."

Son said the results could be boiled down to one key factor: "In one word, Alibaba," he said.

Shares in Alibaba Group Holding, SoftBank's largest single investment, fell more than 30 percent in the three months ended September, according to Bloomberg, as authorities in China embarked on a crackdown on tech firms as part of a drive to tighten their grip on the economy.

The firm also took a hit from DiDi Global, parent of Didi Chuxing, which has also been in Beijing's crosshairs.

DiDi's share price "is dropping under the influence of the Chinese government's regulations. Most of the other Chinese shares we own are also tumbling", Son said.

After the April-June first quarter, Son said he would be taking a careful approach to investments in China, acknowledging "tough challenges".

"We want to be cautious," he said in August.

"New regulations, new rules are being implemented, so until it gets settled we want to wait and see. In one year or two, it will be clearer."

In total, the firm said its loss on investments during the quarter amounted to 1.66 trillion yen, including a loss of 321 billion yen for DiDi Global, and 1.21 trillion yen from its stake in South Korean ecommerce firm Coupang.

SoftBank's investments in volatile tech firms and start-ups have made for unpredictable earnings.

In 2019-20, it reported a record net loss of 961.6 billion yen as the start of the pandemic compounded woes caused by its investment in troubled office-sharing start-up WeWork.

But it then reported Japan's biggest ever annual net profit in 2020-21, driven by tech-share rallies as people moved their lives online during the coronavirus pandemic.

Writing last month, Kirk Boodry, an analyst at Redex Research, warned of a "tough" earnings report for SoftBank.

"China exposure is a major driver whilst Coupang continues to spiral down from the heady highs in March."

As usual, SoftBank did not issue an annual forecast, with its business model increasingly dependent on often volatile stock market activity.