It is unusual to see multiple bubbles in offbeat asset classes so close to each other. But this is exactly what happens when you mix an overabundance of enthusiasm with a shortage of investable assets in a new and exciting industry.

Back in the late 1990s, all a company had to do to drive its stock price higher was announce a new internet strategy and add ".com" to its name. Both underfunded, old-line companies and IPOs that either went public way too early in their development or had no business being in existence at all had eye-popping stock prices.

Hypercharging the interest were new investment products that focused on this trend as if it were an asset class unto itself. Over the long term, many broad technology funds have done well, but there were also plenty of internet funds that cratered. It was the speculative part of the tech bubble that we refer to today mainly as the dot-com era.

Now there are multiple asset managers trying to get cryptocurrency ETFs approved by the Securities and Exchange Commission, along with marijuana ETFs, one of which passed $1 billion in assets (in Canada), and the ETFMG Alternative Harvest ETF (MJ) in the United States, which is now over $500 million. Diversification is a better option than betting on a single stock in a volatile sector, but did diversification help when the crypto/blockchain bubble popped?

The crypto-craze inflated and popped at warp speed. Overstock.com rose from the mid-teens to almost $90 per share last year because it announced crypto initiatives. It's down about 70 percent since then, and keep in mind that Overstock.com was a real company with an operating business.

Pot stocks — or cannabis stocks, if you want to use the more respectable name — are rising to unheard-of valuations. Tilray reached a valuation of over $20 billion in wild trading last week that made it larger than companies in the S&P 500. At one point it rose 15 times its trailing 52-week low. Tilray went down almost 50 percent from the high it reached last Thursday, but it still ended last week with a gain of 13 percent and a valuation around $11.5 billion. But by the close of trading on Monday, the entire gain in Tilray shares from last week had been wiped out.

There's a reason that a hedge fund that shorted the crypto bubble is now focused on marijuana stocks.