Chinese electric-vehicle (EV) maker BYD (BYDDY -1.46%) has raised $3.9 billion by selling new shares on the Hong Kong market, according to The Wall Street Journal. The automaker initially planned to raise $3.6 billion, but increased the offer, taking advantage of high investor interest in the sector. 

Other growing Chinese EV companies, including NIO (NIO -5.00%) and XPeng (XPEV -3.35%), have also recently raised fresh capital as stock prices have soared. XPeng raised almost $2.5 billion last month, while NIO has added more than $4.5 billion to its balance sheet since December in two separate offerings. 

BYD Han electric sedan

BYD Han electric sedan. Image source: BYD.

Warren Buffett first invested in BYD in 2008, and Berkshire Hathaway (BRK.A 1.18%) (BRK.B 1.30%) has 25% ownership in the company. The automaker sold almost 131,000 battery-electric vehicles (BEVs) in 2020, and more than 460,000 vehicles overall. Though its BEV sales were down 11% in 2020, BYD outsold rivals like NIO, which delivered 43,728 total vehicles in 2020. 

Investors are betting that EV growth in China will continue, and have been piling into these companies' shares over the past year. NIO is now valued at about the same level of BYD, after its stock has gained more than 1,000% over the past year. 

BYDDY Chart

BYDDY data by YCharts.

Chinese EV makers are raising money to increase production capacity as China aims to produce 5 million EVs by 2025, compared to about 1.1 million in 2020.