June was a great month for NIO investors, with the company’s stock rising nearly 40% from below $40 to over $50.

NIO’s June started with the release of May’s delivery figures. The company delivered 6,711 vehicles during the month, down slightly from April and the second consecutive decline.

There has been a lot of talk about its possible launch of a sub-brand into the mass market. In May, a codename called “Gemini” first sparked the rumors, but in June company executives said “Gemini” was not a sub-brand but would remain a premium positioning.