Zoom founder Eric Yuan has transferred about 18 million of his shares worth more than $6bn (£4.4bn), according to a regulatory filing.
Mr Yuan, who is also chief executive of the video-conferencing platform, moved roughly 40% of his stake in the company last week.
The shares were shown as gifts to unspecified beneficiaries last week.
Mr Yuan has seen his personal wealth rocket as Zoom became a household name during pandemic lockdowns.
An increasing number of students and professionals connected online boosting the fortunes of Zoom and its founder.
Mr Yuan started Zoom in 2011 and listed it on the US stock market in 2019, making him a billionaire. He is currently worth $13.7bn, according to Forbes.
A Zoom spokesperson said the transfers were related to Mr Yuan’s estate planning practices. “The distributions were made in accordance with the terms of Eric Yuan and his wife’s trusts.”
Zoom’s shares have nearly tripled in the past 12 months and the company has a market valuation of around $100bn.
“Zoom founder Eric Yuan’s decision to transfer more than a third of his stake will raise some eyebrows,” Edward Moya, at trading firm Oanda, told the BBC.
“While a Zoom spokesperson noted that the transfer is consistent with the Yuans’ typical estate planning practices, investors will be nervous until we find out who is the recipient of the stock,” he added.
“Yuan is only 51, married and has three children, so the distribution of his wealth could be viewed as rushed.”