(Bloomberg) — SpaceX jumped for a third straight day on Tuesday, putting it on track to overtake Amazon.com Inc. in value and briefly making it the world’s fourth largest stock ahead of Microsoft Corp.

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Shares were up about 13% at 1:00 p.m. in New York, paring some of a gain that had reached as much as 17% earlier in the session. That puts its market value at almost $2.9 trillion, about $200 billion above Amazon’s. At its intraday high, the market value of Elon Musk’s rocket and AI company reached nearly $3 trillion.

At least some of the price action since its debut has been driven by the relatively small number of SpaceX shares available to trade, with only about 4.2% accessible on day one. That can make trading more volatile, with the stock more prone to large swings that can quickly change its market value.

“That is a factor. We’re talking about a company that has very limited shares available for the public versus the headline market capitalization,” said Angelo Kourkafas, senior global investment strategist at Edward Jones.

The gains in SpaceX shares are a sign of consistent investor demand for the stock, calming fears that the record IPO would be too large for the market to digest. The performance paves the way for potential public offerings this year from artificial intelligence competitors Anthropic PBC and OpenAI, both expected to be in the $1 trillion valuation range.

SpaceX announced Tuesday that it has formally agreed to take over Cursor in a deal that values the AI coding startup at $60 billion. Cursor investors will have the right to receive SpaceX stock based on the implied equity value of Cursor, according to a company filing.

Retail traders have also been a key driver of the hot start, buying as much SpaceX stock over its first two days of trading as they purchased across the entire US stock market last week, according to data from Vanda Research.

Tuesday also marked the start of trading for SpaceX options contracts on exchanges including Cboe Global Markets Inc. and Nasdaq Inc., an event that could stoke even more volatility in the stock. Other options exchanges, including those owned by Intercontinental Exchange Inc.’s NYSE and Miami International Holdings Inc., are also expected to list early next week.

When traders buy calls, market makers on the other side of the trade hedge their risk by purchasing shares equivalent to their derivatives exposure. That exposure rises as shares rally, potentially forcing the market makers to pick up additional shares to keep positions balanced, adding to momentum.

More than 1.1 million lots of options traded as of 1:00 p.m. in New York as traders jumped in to bet on further gains in SpaceX.

“The float is absolutely part of this. Index inclusion is coming too, which turns passive funds into forced buyers against a tradable supply of less than 5% and that mechanical demand meeting almost no supply amplifies every move,” said Dave Mazza, chief executive officer of Roundhill Financial.

Nasdaq Inc. changed its rules to allow faster entry to shares of huge companies like SpaceX, which could be included in the index in the coming weeks. That would lend support to the stock price as funds that track indexes will be forced to buy SpaceX shares. S&P Dow Jones Indices decided not to change its rules to allow new IPOs faster entry, meaning SpaceX won’t be immediately included in the S&P 500.

Still, market watchers anticipate shares will face increased downside pressure once insiders are able to sell more stock as so-called lock-up agreements begin to expire. The initial batch of shares will be eligible to be sold after SpaceX’s first earnings release, with some contingent on the share price at the time. Musk’s entire stake, meanwhile, is locked up for the first year of trading.

“We will not know the real clearing price until the lockups start rolling off after Q2 earnings and actual supply meets this demand,” Mazza said.

–With assistance from Bernard Goyder.

(Updates details on index inclusion, trading throughout.)

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