Nio opened up 15 percent to HK$165.6 in Hong Kong, a new high since August 16. The company gained 13.52 percent in the US overnight.

Nio shares traded in Hong Kong surged today, following a big gain in the US market overnight.

The electric vehicle (EV) maker opened up 15 percent to HK$165.6 in Hong Kong, a new high since August 16.

As of press time, Nio's local peer Xpeng Motors was up about 2 percent and Li Auto was down 1.35 percent.

Nio's surge may be related to the strong initial acceptance of the company's new sedan ET5.

Nio unveiled the ET5 at its Nio Day 2021 event late last year and began accepting pre-orders. On September 9, Nio began allowing users to lock in orders while closing the reservation channel. First deliveries of the model are expected to begin on September 30.

Over the past few days, images circulating on Chinese social media have shown Nio's showroom packed with visitors checking out the ET5, similar to what happened when the China-made Tesla Model 3 first began deliveries in the country.

Prior to that, Nio reported second-quarter earnings on September 7 that showed it posted revenue of RMB 10.29 billion ($1.5 billion) for the quarter, beating market expectations of RMB 9.8 billion.

Nio reported an operating loss of RMB 2.85 billion in the second quarter, up 272.8 percent year-on-year and 30.0 percent from the first quarter, according to its earnings report.

After the second-quarter earnings report, two factors will drive Nio's outperformance and make it emerge as a leader among EV upstarts, analyst Edison Yu's team said in a research note sent to investors on Monday titled "Finally time to shine bright."

Those two factors are, according to the team:

First, the ET5 mid-size sedan could become a top-selling premium model (amongst EV and ICE) in short order with initial customer reception being exceedingly positive and production leveraging Nio's new plant.

Second, while Nio's existing gen-1 products are older and more expensive than competing products, they continue to deliver relatively stable volumes; we believe this represents thoughtful pricing and emphasis on branding + service.

Yu's team maintains a Buy rating on Nio and reiterates that the company is its top pick among China's electric vehicle companies.

Nio rose 13.52 percent to $21.75 at the close of US trading overnight, hitting a new high since August 11. Hong Kong stocks were closed Monday for the Mid-Autumn Festival holiday.

NIO sees its 'Model 3' moment as ET5 starts locking in orders