What happened

Shares of Chinese electric vehicle (EV) maker Nio (NIO -1.81%) haven't had a good week. Nio's American depositary shares have steadily declined over the past five trading days for a total of nearly 10%. That includes today's 4.4% drop, as of 12:20 p.m. ET. 

So what 

Investors are starting to feel the weight of a string of macroeconomic news out of China that could impact Nio and other EV makers there. Earlier this week, data released by China's National Bureau of Statistics (NBS) showed a number of key economic indicators fell short of expectations. That led the People's Bank of China to lower interest rates by 10 basis points, in part to help spur consumer demand.

That comes just as manufacturers like Nio have been ramping production back up after COVID-19-related lockdowns stymied both production and demand for electric vehicles this past spring. Most recently, a drought in central China has led authorities to have manufacturers cut back on power consumption. While those restrictions are ongoing, and ultimate impacts aren't yet known, Nio and other EV makers may be affected by a drop in battery production due to the drop in hydroelectric power supply. 

Now what

Nio has also recently formed an independent committee to investigate accusations by a short-seller that the company has been misrepresenting revenue related to its battery swap station subscription program. Management doesn't believe there is any impropriety in how that revenue is reported, but it remains an overhang for investors. 

While there are many ongoing challenges, the company is still working to expand its market into Europe and eventually North America. But the latest spate of negative news has the momentum in Nio shares going down this week. For those that see long-term promise in the company, that could make for a good opportunity to add shares to an aggressive portion of a diversified portfolio.