What happened

Shares of Chinese electric-vehicle maker NIO (NYSE:NIO) were trading lower on Friday. As of noon EST, the company's American depositary shares were down about 5.2% from Thursday's closing price.

So what

It wasn't immediately clear why NIO's shares were trading lower. There was no negative news from the company -- on the contrary, earlier this week NIO reported record deliveries in November and said that it's accelerating plans to boost production due to high demand.

A NIO ES8, an upscale three-row electric SUV

NIO's deliveries broke another record in November. Image source: NIO.

But there have been a couple of developments amid NIO's peer set that may have moved some of the company's investors to take money off the table. A secondary offering from rival Li Auto (NASDAQ:LI) priced at $29 on Friday morning. That was significantly below Thursday's closing price ($32.31), a hint that Wall Street's appetite for Chinese electric-vehicle start-ups might be fading.  

NIO's shares also fell on Thursday, after a Wall Street analyst cut his rating on another rival, XPeng (NYSE:XPEV), from buy to neutral, saying in essence that after its recent 200%-plus gain XPeng's shares appear fully valued. (XPeng's shares were also down yesterday.) 

Now what

As we all know, stocks can and do move up and down for no apparent reason. In this case, it might be nothing more than traders taking profits or reallocating capital. After the tremendous bull run that NIO's shares have had over the last several months, it wouldn't be surprising if some investors were choosing to take profits ahead of year-end. 

But that said, for auto investors who plan to hold NIO's stock for the long term, there didn't appear to be any news to worry about on Friday morning.