: A masked man carries a giant fake marijuana joint August 12, 2001, at the ''Smokey Bears Picnic'', a pro-marijuana gathering in Portsmouth on the South coast of England. The gathering was to raise awareness for the decriminalisation of marijuana in the UK. Sion Touhig/Getty Nine states will vote in November on whether to legalize medical or recreational marijuana, or both.

Leading up to the elections, the industry's penny stocks are trading as if most states will say yes to legalization.

Shares of marijuana firms that trade over-the-counter — not via central exchanges like the Nasdaq — are rallying in the run-up to the votes.

Companies in the industry struggle to get approved to list on the major exchanges partly because marijuana is still illegal under federal law.

Here's General Cannabis Corp., which leases space for companies to grow the plant:

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And here's Cannabis Sativa, which Libertarian presidential candidate Gary Johnson was CEO of until he resigned in January. It has a subsidiary that makes moisturizers and lip balm.

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Here's United Cannabis Corp., a provider of medical cannabis treatments:

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A number of other marijuana penny stocks — priced below $5 a share — have run-ups like these, which are speculative in nature. Briefing Trader shared the following set of charts on Twitter:

The results of the votes next month could be a huge deal for the industry. California's vote is considered the most crucial given the state's size; its economic output in 2015 made it the sixth largest economy in the world, ahead of countries like France.

Earlier in October, Pew Research published a poll that showed that 57% of US adults say marijuana use should be legalized. A decade ago, just 32% were in favor of legalization.

The best companies would stand to profit even more in the industry, which is projected to grow to nearly $21 billion by 2020, according to Arcview Market Research.