The recent decline in the Nasdaq has sparked concerns of a potential tech stock unwind similar to the dot-com bubble burst in 2000.Market professionals highlight lessons from the 2000 crash that investors should heed in 2025.It has been 25 years since the dot-com crash, and worries about a tech bubble resurfacing are on investors' minds.The Nasdaq Composite slumped 78% from its peak in 2000 to the low in 2002, lasting almost three years.Investors are questioning if the rise of artificial intelligence has led to another market bubble.Experts caution about understanding the phases of a market cycle, such as overexuberance, concern, and panic.Valuations play a crucial role, with a focus on monitoring stock price-to-earnings ratios like the S&P 500's forward P/E.While the current market isn't flooded with profitless firms as in 2000, companies with high valuations are being closely watched.Despite past bubbles, the significance of technological advancements like AI is acknowledged by experts.Market analyst Belski believes the current market is not in a bubble, emphasizing the differences from the dot-com era behavior.