Well, that was fast.

Elio Motors, the upstart car company that went public using an update to fundraising rules from the Jumpstart Our Business Startups (JOBS) Act, took exactly two trading days to achieve a value of more than a billion dollars.

The jump in the company's market cap is particularly noteworthy given how many highly valued private companies have seen their private share prices knocked down in recent months, and that the IPO market generally has been quiet in 2016. Elio went public over the summer, raising $17 million from 6,600 unaccredited investors, using a crowdfunding platform called StartEngine. (An unaccredited investor has a net worth of less than $1 million, or an annual income less than $200,000.)

In June, the Securities and Exchange Commission (SEC) altered a decades-old rule called Regulation A, which allowed private companies to solicit funding from wealthy investors up to $5 million. The update, called Regulation A+, allows private companies to raise money in two tiers, for amounts up to $20 million and $50 million, including from unaccredited investors.

Elio, which trades on the OTCQX Market, an exchange for smaller companies, has 25 million shares outstanding, according to its September SEC filing. Frequently, companies move from the OTCQX to larger exchanges, such as Nasdaq or the New York Stock Exchange. But during a public forum last Thursday, company founder and chief executive Paul Elio said he had no intention of moving anytime soon.

On its first day of trading, Elio's shares increased 17 percent, to $16.50, after pricing to open at $14. By end of day Monday, they had jumped to $60, giving the company a market cap of $1.5 billion, roughly triple its value when shares began trading.

Elio, based in Phoenix, manufactures an aerodynamic three-wheel car capable of getting 84 miles per gallon. The cars, which will sell for a base price of $6,800, will begin production in late 2016, according to a company spokesman.