While many are rejoicing over the Nasdaq's close above 5,000 for only the third time in its history, analyst Peter Boockvar isn't impressed.
"If you look at the S&P 500 and the Dow Jones, they've exceeded their inflation-adjusted 2000 high. The Nasdaq needs to rally another 36 percent just to get to its March 2000 inflation high," the Lindsey Group's chief market analyst told CNBC's "Squawk Box" on Tuesday. Boockvar added the Nasdaq's closing number on Monday's session is only nominal.
Before Monday, the Nasdaq Composite had last closed above the 5,000 mark on March 9 and 10, 2000.
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Boockvar said investors should be cautious when investing in Nasdaq companies, as stocks within the index remain expensive despite valuations not being what they were in 2000. He added that Nasdaq stocks have been driven mainly by low rates and quantitative easing rather than earnings growth.
Nevertheless, Boockvar said today's Nasdaq is dominated by healthier, more profitable companies than in 2000.
Another analyst, however, said he believes the skepticism around the Nasdaq this time is a good sign. "Individuals are a little skeptical about the market, unlike during [2000]," Rick Sherlund, managing director at Nomura Securities, said on "Squawk Box." "You're not getting stock tips from cab drivers [anymore]."
The Nasdaq has changed fundamentally since 2000, Sherlund added. "Valuation underpinning looks very different. The composition of the Nasdaq looks very different. We had seen over 600 IPOs in 1999 and 2000, [and] we saw a little over 50 last year. Companies are largely cash-flow positive now, so the balance sheets are very different," he said.
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—CNBC's Kristen Chang contributed to this report.