What happened

After a terrific Tuesday, shares of marijuana stocks are getting stubbed out on Wednesday.

As of 1:30 p.m. ET, Tilray (TLRY 0.58%) shares are down 2.4%, Aurora Cannabis (ACB -1.15%) is down 3.4%, and Canopy Growth (CGC 1.28%) is down 4.3%.

Marijuana joint stubbed out in a metal ashtray.

Image source: Getty Images.

So what

That's actually pretty surprising given that earlier this week, cannabis news source MarijuanaMoment.net reported that Senate Majority Leader Chuck Schumer may finally be willing to give marijuana banking reform a fair hearing in the Senate -- and even permit banking reform to pass before considering a separate bill to legalize weed outright.

It's all the more surprising given that, just yesterday evening, Marijuana Moment also reported that in the U.S. House of Representatives, the Secure and Fair Enforcement (SAFE) Banking Act (which is the official name of the marijuana banking law) has been refiled for consideration, and that the House Rules Committee has OK'd the bill for a vote by the full House this week.  

Already so far, the House has approved the SAFE Banking Act in one form or another five separate times, so passage through the House seems a pretty sure thing. And once that happens, the SAFE Banking Act will go to the Senate, where Schumer will approve it, right? Right?

Now what

And yet apparently, marijuana investors aren't convinced this is a sure thing. Schumer's assurances notwithstanding, investors in marijuana have been burned before, and you know the old saying: Once burned, twice shy.

So imagine how jaded they must feel after having been burned five times in a row already.

At this point, marijuana investors can be forgiven if they're feeling a bit skeptical about the U.S. Congress being able to ever get marijuana legalization done. And even if Congress does succeed in passing what Marijuana Moment observes is actually pretty "modest banking reform," that still leaves the thornier question of absolute legalization of the drug to be accomplished. And even then, there's the very big open question of whether even legalized marijuana is a product that marijuana companies can earn a profit on.

Remember: Up in Canada where the drug has been legal for years, and where both Aurora and Canopy Growth do most of their business, both of these companies are still losing money. Tilray, with operations in Europe as well as in Canada, isn't profitable yet, either. Even if the United States legalizes weed, there's still no guarantee that any of these three cannabis companies will profit from it.

And marijuana investors are probably right to remain skeptical.