Six experts on whether the cannabis craze is a boom or bust

The cannabis craze is hitting Wall Street. Shares of Canadian pot company Tilray have shot up recently during several wild trading sessions, driving more and more investor interest into the global marijuana market.

The ETFMG Alternative Harvest fund, an ETF that tracks the marijuana industry, was up more than 20 percent this month as of Thursday morning.

"Cannabis is one of those great global super-themes," Sean Stiefel, founder of the Navy Capital Green Fund, told CNBC on Wednesday. "We've seen this now in country after country — Israel, Australia, Canada — where people end up voting with their dollars and buying stocks because they are cannabis related."

Stiefel added, "Valuations now have truly gotten ahead of themselves, and the retail investor here is buying air effectively."

Here's what six experts have to say about whether the cannabis craze is worth investors' time.