(Yicai Global) Aug. 7 -- The stock price of Tencent Holdings plunged by as much as 10 percent today in its biggest slump in a decade on the news that President Donald Trump is to block its social messaging app WeChat in the US.

The share price [HKG:0700] later recovered to end the day down 5.04 percent at HKD527.50 (USD68), wiping off HKD300 billion (USD38.7 billion) from its market capitalization.

Yesterday US President Donald Trump extended its ongoing vendetta with popular short video app TikTok to include WeChat in an executive order blocking all US transactions with the two parent Chinese firms from Sept. 20 in order to “address the national emergency with respect to the information and communication technology supply chain,” according to US tech news website The Verge today.

The Shenzhen-based tech behemoth has yet to respond to the US government’s move.

WeChat has more than 1.2 billion users and over 1 billion monthly active users, most of them in China. Around 100 million people use WeChat outside the country, analysts say.

However, social messaging is just one of Tencent’s many global businesses. It is also the world’s largest gaming company and owns the highly popular battle arena game League of Legends’ developer Riot Games, it holds 40 percent equity in Fortnite developer Epic Games and 5 percent in Call of Duty’s publisher Activision Blizzard.

It is also a shareholder in major US firms, including a 12 percent stake in social media firm Snap and 5 percent in electric car startup Tesla. Last year it invested USD150 million in news aggregator Reddit and signed a five-year content sharing agreement with the National Basketball Association worth USD1.5 billion.

It is not clear yet how the new executive order will affect these businesses. Tencent has just rented a 2,400 square meter office in Irvine, California, in one of the golden state’s highest-value office lease deals in the second quarter, according to US commercial real estate website CoStar.

Editor: Kim Taylor