SpaceX's valuation reportedly hit $350 billion after the company and its investors agreed to purchase $1.25 billion of insider shares. Now, founder Elon Musk has revealed that almost none of the existing investors wanted to sell their holdings.

What Happened: The company and its investors agreed to buy insider shares at $185 a share, Bloomberg reported, citing an internal email. SpaceX alone is offering to buy as much as $500 million in common stock as part of the offer, the report added.

The new valuation represents a 67% surge from the company's previous valuation of $210 billion it hit in a secondary share sale in June.

The new valuation makes SpaceX the most valuable private startup in the world. Its valuation, in fact, trumps the valuation of listed rival Boeing Co. Boeing has a market cap of only $122.78 billion as of last close.

Why It Matters: SpaceX is privately held, unlike Musk's Tesla which is a publicly listed company. The secondary offering gives employees and shareholders the choice of selling shares they hold in the company and generating liquidity.

"What's really crazy about this is that almost no investors wanted to sell shares even at a $350B valuation! SpaceX reduced the amount of shares it bought back from employees in order to allow some new investors in," SpaceX CEO Elon Musk said on Wednesday about the insider share sale, confirming the new valuation.

Musk has previously dismissed the possibility of a SpaceX initial public offering (IPO), citing the intense pressure for short-term results faced by publicly listed companies.

Despite SpaceX being private, investors can leverage Destiny Tech100 Inc. (NYSE:DXYZ) and Cathie Wood's Ark Venture Fund (NASDAQ:ARKVX) to participate in the Musk-led space company's growth.

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