What happened

Shares of Chinese electric-vehicle maker NIO (NIO -0.48%) were trading lower on Thursday, amid a broader sell-off of electric-vehicle stocks in China and the United States. 

As of 11 a.m. EST, NIO's American depositary shares were down about 5% from Wednesday's closing price.

So what

NIO was just one of a long list of electric-vehicle makers whose stocks were in the red on Thursday morning. Shares of several others, including NIO's domestic rival Xpeng (XPEV), were also down 5% or more as of late morning. There was no obvious news triggering the sell-off. 

As longtime auto investors know, this sort of thing happens sometimes. News affecting one company, or a shift in economic sentiment, can bring a broader group of stocks down as institutional investors and traders adjust their holdings. That process can appear mysterious to those holding one of the stocks in the group, but it's just part of investing.

That's probably why NIO stock is down today.

NIO CEO William Bin Li onstage with a sleek white electric sedan

NIO CEO William Bin Li showed off a new electric sedan, the ET7, at an event last month. NIO will report earnings on March 1. Image source: NIO.

Now what

I don't think there's anything that longer-term NIO investors need to do right now. January sales were good, the company has plenty of cash on hand, there are new sedan models on the way, and investors can look forward to the company's fourth-quarter and full-year 2020 earnings report after the U.S. markets close on March 1.