The value of his stake had shot up to $4.791 billion by Thursday's close. Spiegel also received an $800 million bonus for taking the company public.
Snap's first week of trading has not been the smoothest, however. After rising 44 percent and 10.6 percent in its first two days of trading, respectively, the stock dropped 12.3 percent and 9.8 percent in its next two days.
Snap shares since IPO
Several Wall Street analysts initiated coverage of the stock with a sell rating, while only a few initiated the stock with a neutral rating, citing valuation and growth concerns.
"I consider myself cautiously optimistic on the company; the stock is just overvalued," said Brian Wieser, an analyst at Pivotal Research Group. Wieser initiated Snap with a sell last week and a price target of $10, representing more than 50 percent downside potential.
"There's certainly a 'Myspace risk' there," he said, meaning the company runs the risk of becoming too commercialized. "After Myspace was acquired by News Corp., they were too aggressive in commercializing and that turned off a lot of users."
He also noted that Snapchat is mostly popular among people ages 12 to 24. When it went public, "Twitter was a niche platform used by a group of different ages across the globe. Snap's platform use is highly dependent on one age group."