Firefly stock tumbled to close down 16.9% on Friday at $50.17. That's still $5 and change more than the initial public offering (IPO) price, but a lot of Thursday's IPO gains got vaporized as sentiment turned against the stock -- or perhaps it's more accurate to say, against space stocks in general.

Firefly Aerospace's ( FLY) stock is sputtering, just one day after its trading debut, when enthusiasm for the new listing sent shares soaring. The space company's stock was down 13% to about $52 Friday afternoon, wiping out more than half its gains in its first day of trading yesterday.

Firefly Aerospace, which successfully landed on the moon in March, is went public today under the stock ticker symbol FLY. It opened at $70 a share, 56% above its IPO price.