Apple advanced 3.4% and was the best-performing component in the Dow Jones Industrial Average. Tesla jumped 12.6%.
Monday's gains were the latest in a string of strong performances since the companies announced the stock splits.
Billionaire investor Leon Cooperman, however, said Monday that run-ups on the back of stock-split announcements are a troublesome sign for the market.
"Look at Tesla and Apple: Everybody understands that splits don't create value," the founder of Omega Advisors told CNBC's "Squawk Box." "My dad once told me if you gave me five singles for a $5 bill, I'm no better off."
Monday's gains in Apple and Tesla came amid high volume as smaller traders are able to snap up shares in both companies at a much lower price than on Friday.
Apple traded 223.4 million shares, which is roughly 25% more than the stock's 30-day volume average of 178.588 million. Tesla shares exchanged hands 115.6 million times, well above its 30-day volume average of 73.369 million.
This year, smaller traders have been more actively participating in the market as commission-free online brokerage Robinhood grows in popularity. But Cooperman sees this as a potential sign of being overheated.
"I see signs of euphoria creeping into the market: the IPO SPAC market is one, [and] the craziness in many of the stocks that the Robinhood crowd has latched onto," Cooperman said. "You see a Kodak go from $1.50 to $60 and from $60 to $6 in a very short period of time … and when you look into it, it's the Robinhood crowd taking it up."
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