The aerospace manufacturer and space transport business was founded by Elon Musk in 2002 and has set a number of records regarding private sector achievements in spaceflight.
Its valuation has been revealed through public filings obtained by Equidate, the marketplace for equity in technology companies, which reveal the company has raised up to $350m in a new funding round.
Mr Musk, 46, has a personal net worth of $16.3bn, according to Forbes.
Specific figures on privately held companies’ valuations are difficult to establish, and those numbers are rarely agreed upon by investors, but very few companies are ever suggested to be worth more than $20bn.
The world’s most valuable public company is Apple, which reached a market capitalisation of $819bn in May 2017.
Adjusting for inflation, Microsoft had the highest ever market capitalisation, peaking at $998bn on 30 December 1999.
SpaceX now sits beside data analytics company Palantir, which is a large government contractor, as well as Uber and Airbnb, as being privately owned but valued at more than $20bn.
The company has also challenged the monopoly of United Launch Alliance, which has provided spacecraft launch services to the US government since 2006.
In recycling its Falcon 9 rockets – where its competitors’ are forced to build new ones for every launch – the company has managed to achieve an economy of business which others have not.
Earlier this year, SpaceX was used to launch a reconnaissance satellite for the US military. Details of what the satellite would be used for are classified.