If you look at cryptocurrencies purely as their own self-contained universe, then we're possibly in a period of "irrational euphoria."

On the other hand, people have been working for years to try to break through to a point where cryptos become a recognized asset class for investment to a much broader market.

So, let's add some perspective:

The classic "dot-com bubble" in high tech stocks took a little over four years going from Nasdaq 1000 to Nasdaq 5000 before the cooking crumbled.

Some size perspective: The total market cap of all cryptos added together is still less than it takes to make it into the world's 100 largest companies, by market value. Point? Cryptos remain a tiny flyspeck in the greater investing universe. If what we're seeing is actually the beginning of "mainstreaming," we have many, many miles to go. The market cap of the Fortune 500 companies is 17 trillion USD, or some 212 times the cap of all cryptos.

That's not so suggest we might not have a short term correction at some point, but it would probably be fairly temporary-- unlike the Nasdaq which took 15 years to hit its 2000 peak.