What happened

Shares of electric vehicle (EV) company Nio (NIO -7.92%) fired up on Tuesday and were up 3% as of 12:10 p.m. ET before popping nearly 6.6% right after market open.

There's a lot happening behind the scenes at Nio not many are aware of: Nio's big day is coming up next week, it just inked a partnership that's not made it to the headlines yet, and there's a rumor floating about Nio's second listing. Here's everything you need to know.

So what

Let's start with the partnership: One of the world's leading car leasing companies, LeasePlan, revealed it had signed a partnership with Nio to offer its flagship SUV, ES8, in Norway. Investors may remember that Nio first announced its official entry into Norway in late September with its first ES8 delivery, but its deal with LeasePlan is the first of its kind for the EV manufacturer in Europe. LeasePlan has nearly 1.8 million vehicles across 29 countries and is committed to achieving net-zero emissions from is fleet by 2030.

Nio SUV ES8.

Image source: Nio.

Meanwhile, Goldman Sachs just reported Nio to be among the U.S.-listed Chinese firms that could be eligible for a listing in Hong Kong, according to the South China Morning Post. I wouldn't be surprised if Nio, indeed, considers dual-listing sometime in the future as it has multiple advantages and should be a great backup at a time Chinese stocks in the U.S. face intense regulatory risks.

Above all, Nio just confirmed via a post on its app that it'll host Nio Day 2021 on Dec. 18, according to CnEVPost, a news portal focused on the new-energy vehicle industry in China. Nio is not only expected to officially launch its sedan ET7 on Dec. 18, but also to unveil two other new models including an entry-level car model, the ET5. Just days ago, CnEVPost posted pictures of what's suspected to be an ET5 sedan on a road in China.

Now what

While I'm not going to read much into the possibility of a secondary listing, Nio's deal with LeasePlan holds a lot of promise as it offers the EV maker a great opportunity to expand its footprint in Europe, especially when it's already planning to launch its ET7 in Norway next year.

All eyes, though, are now on Dec. 18, as the models and growth plans Nio unveils that day will decide where the stock is headed. Earlier this month, Nio already won back investor confidence when it reported a 105.6% jump in its November deliveries, confirming the sharp drop in its deliveries in October was an exception. Nio Day now has investors excited to see what more the already promising EV maker has to offer.