Why it matters: Tesla suddenly finds itself with a serious rival as Lucid lands a $1 billion investment from Saudi Arabia. Had Tesla decided to go private last month as Elon Musk teased, this likely wouldn't have materialized.

Saudi Arabia's sovereign wealth fund on Monday announced it will invest more than $1 billion into electric car start-up Lucid Motors. The backing will help Lucid finance the commercial launch of its first electric vehicle, the Lucid Air, in 2020.

The announcement's timing is perhaps just as interesting as the news itself. That's because last month, Tesla CEO Elon Musk tweeted about the possibility of taking the electric automaker private. Musk said funding for the deal had been secured and later named the Saudi sovereign fund as the basis for that statement.

After thinking it over and listening to feedback from investors, Musk decided Tesla should remain a public company.

Lucid Motors in 2017 said its first electric vehicle would start at $60,000. A few months later, the company demonstrated the car's ability to hit 235 mph in testing. That's far faster than anyone needs to go but the fact that it's technically possible with all that weight from the batteries is impressive.

Around this time last year, Lucid Motors' future was uncertain. Funding was a major issue and Ford was reportedly seriously interested in acquiring the start-up. Now with money from the Saudi fund, those issues are no longer a concern and Tesla suddenly has a true competitor on its hands.