The Dropbox (DBX - Get Report) IPO could easily be the biggest news of the day on Friday.

On Thursday evening, the cloud-solutions business priced its IPO at $21 per share, ahead of the $18 to $20 range previously set. Demand for the stock remains strong, given that the original range was pricing between $16 to $18.

So already now at $21, shares are set to price $4 per share or 23% above the midpoint of the original range. That could be just the start of this stock's upside potential, though, TheStreet's Jim Cramer said on CNBC's "Stop Trading" segment.

As of 11 a.m. ET, Dropbox had not yet opened for trading, when Cramer made his comments. However, the stock did open near midday trading and Dropbox did not disappoint. Shares exploded higher, hitting a high of $31.60 before retreating and closing at $28.48, up more than 35% for the session. 

Cramer considers Adobe Systems Inc.  (ADBE - Get Report) one of the "cloud kings," a best-of-the-best in the industry.

It's recent earnings make it hard to refute that claim.

In any regard, Cramer, who also manages the Action Alerts PLUS charitable trust portfolio, pointed out that Adobe stock trades at 10.4 times 2019 revenue estimates. And remember, this is considered one of the best in the business.

Does Dropbox deserve a similar premium? If so, that would put the stock at about $35, he reasoned. There will be investors comfortable paying that valuation, said Cramer, who also pointed out that 8 times 2019 revenue estimates would put Dropbox near $30 per share

The valuation will be set by investors, but Cramer wants them to know how it compares to the industry's best. In this case, that's Adobe. 

At the time of publication, Cramer's Action Alerts PLUS had no position in any security mentioned.