The company's shares opened at $14.50, a more than 20% increase from the offering price, before closing at $13.50.
"The losses here are staggering" for the business, Cramer said on "Squawk on the Street."
Casper, which started out selling mattresses on the internet five years ago, had a loss of $92.1 million in 2018 and $73.4 million in 2017 on net revenues of $357.9 million in 2018 and $250.9 million in 2017. Casper has both high-profile investors, such as actor Leonardo DiCaprio, and high-profile partnerships with retailers such as Costco and Amazon.
The New York-based company announced plans for an initial public offering in early January and had initially planned to price its shares between $17 and $19.
However, Casper ended up pricing its IPO on Wednesday evening at $12 per share, giving the company a market value of $476 million. That's dramatically lower than the $1.1 billion valuation from its latest round of private funding.
"They may have priced it to move," the "Mad Money" host said, referencing a strategy in which companies lower their offering price in hopes of creating a first-day pop, which indeed happened.
"You cut and cut and cut; you can get a deal to work, any deal to work," he added. If the shares are priced too high on their first day, they could fall and create less-than-ideal optics.
Philip Krim, 36, co-founder and CEO of Casper, later told CNBC on Thursday that "valuations are moments in time" and his focus is on the future and growing the company.
Appearing on "Squawk Alley" shortly after the stock opened higher, Krim said: "I feel awesome. It's been a great day. It's an awesome milestone for Casper. So I'm pumped."
Casper's IPO is taking place in a "post-WeWork apocalypse" world, Cramer said.
The WeWork saga is viewed by many as a turning point for how public market investors view money-losing start-ups, helping to shift focus away from growth at all costs and reemphasizing the bottom line and a path toward profitability.
The coworking company pulled its IPO and its CEO, Adam Neumann, stepped down in September following backlash over WeWork's governance and valuation ahead of its expected offering. WeWork had picked up a $47 billion valuation in the private markets, but some public investors came to value the company as low as $10 billion.
Cramer said he thought Casper ultimately was wise to lower its price per share targets before it began trading to avoid the pitfall of tighter valuation scrutiny in the current climate in the public markets.
"This is one of those deals where if they had brought it higher it would have been crushed," he said. "They really have been very good about where to do it. It's a very small deal."
While Casper began selling mattresses online through a direct-to-consumer model, it has since opened 60 retail stores, with goals to have upward of 200. It also expanded its product offerings to include bedroom furniture and fixtures such as pillows and lamps.
But Cramer cast doubt on long-term demand around Casper's core product. "It's a bed that is mailed. ... It's not exactly Clorox wipes when you're on a subway car, in terms of demand."
Cramer also weighed-in on Twitter on Casper's IPO before the stock market opened Thursday.