It is probably a testament to the growing acceptance of marijuana in certain states that FINRA, the largest independent regulator of securities firms doing business with the public in the United States, felt the need to issue a special Investor Alert this week called "Marijuana Stock Scams." 

Medical marijuana is now legal in almost 20 states and has been recently legalized in the states of Washington and Colorado. Bloomberg estimates that the move toward legalization of marijuana "has the potential to start a $35 billion to $45 billion a year industry." According to FINRA, these developments have led the investing public and securities fraudsters to begin seeing dollar signs in the "cannabis business."

FINRA specifically warned investors to watch out for "pump and dump" scams, which investors may encounter through "faxes, email or text message invitations to webinars, infomercials, tweets or blog posts" about marijuana-related companies. The scam, FINRA stated, is designed to create demand for thinly-traded companies that will allow the fraudsters to sell off their shares at a profit. A FINRA spokesperson told Bloomberg that with marijuana business now being perceived as "the next big thing, the cons tend to circle around.”