SoftBank's shares are down 10% amid broader tech sell-off

Shares of SoftBank fell 10% following an overnight sell-off in the U.S. market on the back of wider profit taking in the tech sector. Other Asian tech giants also saw their share prices fall.

While the Japanese investment giant recently overtook Toyota Motor as Japan's most valuable company, there are market concerns over SoftBank's high-risk bets on AI, even as its share price has risen about 70% year-to-date on investor enthusiasm over the new technology.

SoftBank CEO Masayoshi Son told CNBC he expects the AI revolution to be 50 times larger than the dot-com revolution of the 2000s.

"Now, if you look at the history, electronics and motorization crashed in 1929, but went up for many, many years, for the next 100 years after that … so there may be some correction, but that will be the best investment opportunity to me," Son said on Monday.

The market appears "to become fixated on short-term momentum, and less interested, or unable, to map out the long-term trajectory with detailed assumptions," according to a recent investor note by Deutsche Bank analyst Peter Milliken.

Over in South Korea, Samsung and SK Hynix saw their shares decline by 1.25% and 2.75% respectively amid some profit taking, after both companies each crossed a market valuation of $1 trillion in May.

SoftBank's shares last traded 10.6% lower at 7,434 yen.

—CNBC's Lee Ying Shan and Sawdah Bhaimiya contributed to the report.