Tesla shares have skyrocketed recently and earlier this week, hit US$420 for the first time in the automaker’s history.

Those familiar with Tesla will know that $420 is a rather significant figure for the company as it is the price Elon Musk infamously claimed he had the “funding secured” for to take Tesla private. As recently as May this year, Tesla shares were trading below $200.

Musk, clearly happy with where Tesla shares are sitting, took to Twitter celebrating the milestone, writing “Whoa…the stock is so high lol.” In cannabis culture, 420, 4:20 or 4/20 is slang for smoking weed. The code is believed to have originated from the early 1970s when a bunch of high-school kids got into the habit of meeting at 4:20pm to smoke marijuana. Since then, April 20 or 4/20, has become an international holiday for cannabis culture.

Also Read: Elon Musk Considering Taking Tesla Private, Has Already Secured Funding

With a share price of $420, Tesla’s market capitalization has hit roughly $76 billion while Musk’s stake is now worth $15.2 billion on paper. This year, Tesla’s stock is up almost 27 per cent and brings to an end an important 12 months for the brand headlined by a series of significant announcements. For example, it unveiled the Cybertruck a little over a month ago, premiered the Model Y earlier this year, recently opened its production facility in China, and has announced its intention to build another Gigafactory in China.

When Musk claimed to have the funding secured to take Tesla private at $420 a share, the U.S. Securities and Exchange Commission quickly triggered an investigation into the remark. Musk was issued with a $20 million fine while Tesla was also hit with a $20 million fine. In addition, the outspoken chief executive was forced to step down as chairman and must have public statements about Tesla’s finances vetted by a legal counsel.