NBCUniversal's $500 million investment in Snap is a "wake-up call" for short sellers, CNBC's Jim Cramer said Friday.
"Those who were shorting it ... they're already screaming. You can't short when you start these new deals by the way, but people do. That's going to be a wake-up call. There's going to be a lot of deals announced with media companies," Cramer said on "Squawk on the Street."
The stock allocation by Snap to NBCUniversal appears to be the only one made to a new strategic investor, which would make NBCUniversal the only U.S. media company with a stake on the IPO day.
"This is a significant milestone in our growing partnership with Snap, and we look forward to participating in Snap's success as an investor and continuing to work closely with them for years to come," NBCUniversal President and CEO Steve Burke said an internal memo to employees.
Snap has had mixed reactions from the Street and has yet to receive a buy rating from any analyst listed in FactSet.
Snap's stock extended its IPO gains on Friday, rising about 13 percent after the news about NBCUniversal's investment.
Disclosure: Jim Cramer's charitable trust owns shares of Comcast.
—CNBC's Andrew Ross Sorkin and Anita Balakrishnan contributed to this report.