Investors love to know what famous Wall Street billionaires are buying, and every quarter, the Form 13F filings they make with the Securities and Exchange Commission provide the public with just that information.

Those forms reveal what assets institutional investment managers hold in the funds they manage, and the latest one from George Soros' investment fund showed that Soros Fund Management started buying shares of Chinese EV maker Nio (NIO 1.04%) in the first quarter. 

That news helped boost the stock Monday morning. The session's gains come on the heels of a downtrend in the stock that has lowered the price by more than 25% in the last month, and by 50% so far in 2022. Investors have been negative on the EV maker for a number of reasons, but Soros seems to think shares are a buy. 

red Nio ES6 SUV on tree lined street.

Image source: Nio.

Nio only made up about 1.3% of Soros' portfolio as of the end of Q1, but that filing was the first time the billionaire reported investing in Nio. He likely had several reasons for adding it to his fund, and it's worth considering whether they make the shares a smart buy for retail investors, too. 

The China electric vehicle maker's stock took a hit recently after strict COVID-19 lockdowns in major manufacturing hubs in China disrupted supply chains. Nio is one of many automakers there that have suspended production due to a lack of parts. As the Chinese government has started to ease those lockdowns, however, manufacturing has begun to pick back up. And the bigger picture is that Nio is debuting new models this year, and also expanding in the European market, where it began to operate last year with a presence in Norway. There have also been recent reports that its previously discussed plans for a mass-market sub-brand may be coming to fruition. 

Nio remains a speculative investment in an immature, but growing, sector. Those looking at its long-term potential might want to follow Soros, however, as shares are down due to shorter-term headwinds. The company's cheaper valuation combined with its promising potential might be what brought Soros into the stock.