Drew Houston and Arash Ferdowsi at the Nasdaq market site during the Dropbox IPO, March 23, 2018.

In honor of Dropbox's long-awaited IPO, an early investor unearthed a decade-old memento: Two checks made out to Dropbox co-founders Drew Houston and Arash Ferdowsi, the year they founded the cloud storage company.

The checks represent the very first investments that helped get Dropbox off the ground.

Jessica Livingston, co-founder of seed stage investment firm Y Combinator, wrote a $3,000 check to Houston and a $12,000 check to Dropbox's parent company, Evenflow.

On Friday, after the company went public, its market value hit as high as $12 billion.

Y Combinator President Sam Altman posted an image of the checks in a tweet.

@sama tweet

"Congrats to @drewhouston and @arashf--we found the checks @jesslivingston wrote you in 2007 for YC! Long way since," Altman wrote on Twitter.

Livingston re-tweeted Altman, joking about her messy signature.

@JessLivingston tweet

Dropbox's IPO is the first of a pair of anticipated tech IPOs this year and the largest since Snap's IPO last year.

Despite an especially challenging week for tech, in the wake of Facebook's recent data scandal, Dropbox's performance could be an indicator of strength in other tech "unicorns," or young companies valued at more than $1 billion.

Dropbox started trading on the Nasdaq on Friday. Dropbox priced its IPO above expectations at $21 per share on Thursday night, valuing the company at more than $8.2 billion. Minutes into its first day of trading, the cloud storage provider's shares jumped more than 40 percent.