What happened

Nio (NIO 0.38%) stock fired up this week -- and how. Barring one down day, the shares rallied every other day and were up a whopping 28% through the week as of 11:45 a.m. ET Friday, according to data provided by S&P Global Market Intelligence.

Nio is growing rapidly, as its latest delivery numbers suggest, but this week's epic rally was driven almost entirely by one macroeconomic trigger. That one trigger alone attracted big investors into Nio, as they perhaps see it as a surefire sign of an end to the biggest overhang on the electric vehicle (EV) stock.

For that matter, Nio's CEO William Li also had some big things to say this week, including his belief that Nio will give German luxury carmaker BMW a run for its money.

So what

Because Nio is a Chinese company, its stock price has been all over the place in recent months as China grappled with surging COVID-19 cases and put large regions, including important manufacturing hubs, under strict lockdowns. 

In a significant -- and surprising -- turn of events this past weekend, though, mass public protests against Draconian zero-COVID policies erupted in China, fueling hopes of an easing in restrictions and an economic upswing.

On Wednesday, the nation lifted some COVID restrictions in some areas. The Hang Seng index clocked its biggest monthly gains since 2003, and Chinese stocks in the U.S. skyrocketed. Nio shares surged by double-digit percentages.

Although most Chinese stocks took a breather the next day after their dizzying one-day rally, Nio revealed record delivery numbers for the month of November, in line with its outlook.

Nio's November deliveries rose 30% year over year and 41% sequentially, and it grew faster than peers overall. While Nio's ES7 SUV saw a big jump in sales, the company also sold 2,968 units of its newly launched sedan, ET5, which is touted to be a potential game changer for the EV maker.

Now what

While the markets may have focused only on the China angle this week, investing in a Chinese stock on expectations and speculation about the economy is still about as risky as it can get. Of course, any rebound in the Chinese economy will bode well for Nio, but investors should buy the stock for what the company is doing and can do, even in a challenging business environment. Nio doesn't disappoint on that front.

This week, Nio said it will accelerate production and deliveries in December, which means the company could meet its guidance of record deliveries in December and 75% or higher growth in revenue in the fourth quarter. Further, in a speech to employees this week on Nio's eighth anniversary, Li spoke about the company's goal to break even by 2024 and produce its own batteries and semiconductor chips in the long term.

Li also said Nio is now focused on increasing sales, and he is so confident about its EVs that he believes anyone who drove a BMW will not go back once they buy a Nio vehicle.

I have been pounding the table on Nio stock for several weeks now, and this week just proved how quickly investor sentiment in the stock can change.