Another tranche of SpaceX stock will be unlocked and free to trade next week. It will be the second since the company came to market two months ago.

Shares have gained around 22% in the week since the first chunk of shares were unlocked last Thursday.

The stock was rising again in Friday's premarket, up 0.9% to $142.55. It's down more than 6% since it began trading two months ago on June 12 and has fallen 30% from its record high of $201.80 reached a few days later on June 16.

And it could face more turbulence as a rival reusable rocket company appears on the horizon.

Start-up Stoke Space Technologies Inc . is raising $1 billion to accelerate development and production of a fully reusable rocket to challenge Elon Musk's company, Bloomberg reported citing people familiar with the matter.

SpaceX has a near-monopoly on global commercial satellite launches with more than 90% market share. It's the go-to launch company for small payload satellites because of its reliability. Developing reliable rockets is not easy -- just look at Jeff Bezos' Blue Origin.

In April, its New Glenn rocket's third flight carrying AST SpaceMobile's BlueBird 7 satellite hit an engine problem and the second stage failed to reach the target orbit, leaving the satellite off its nominal path. This followed an explosion in May while a New Glenn rocket was static, destroying the vehicle and damaging the Cape Canaveral Launch Complex in Florida.

Elsewhere, Virgin Galactic's Virgin Orbit attempted to kick-start launches from the U.K. but its only liftoff ended in the ocean, which triggered a severe liquidity crisis. Virgin Orbit failed to secure funding, filed for Chapter 11 bankruptcy in April 2023, and ceased operations.

Musk won't be worrying about the nascent competitor just yet. What he will be watching, along with Wall Street, is how the market reacts to the next tranche of SpaceX shares to hit the market on Aug 20.

The world's richest person held a 48.4% stake in SpaceX as of June 30, according to a regulatory filing on Thursday -- that's worth nearly $906.9 billion based on Thursday's closing price.

The market widely expected a selloff after the first lockup period ended. That didn't happen, but it could next week and investors will be approaching the release cautiously.