For every solid investment opportunity to come rushing out of the gates like a well-bred horse, there is a dark side: cheats, scam artists and sleaze swindlers; all looking to put a stranglehold on the hard earned dollar of the average citizen.

Unfortunately, the legalized marijuana trade is no exception, and it is for that very reason that the Financial Industry Regulatory Authority, commonly referred to as FINRA, delivered a warning to pot stock investors earlier this year, urging them to keep their eyes peeled for the inevitability of cut-throat cons and other rackets looking to capitalize on this rapidly growing industry.

“With medical marijuana legal in almost 20 states and recreational use of the drug legalized in two states, the cannabis business has been getting a lot of attention -- including the attention of scammers,” according to the FINRA alert.

The most common scam, according to the FINRA warning, is the infamous “pump-and-dump” scheme: where a thieving mastermind entices investors with a very promising opportunity, cleverly getting them to sink money into a veritable toilet stock using padded financial statements.

The hammer comes down after the scam artist sells off their shares for a profit and leaves the bamboozled investors in the doghouse chewing on mutt stocks.

Even though the investor should always conduct the appropriate due diligence to ensure investments are on the up-and-up, especially in the pursuit of marijuana stocks with no real company history or proven track record, not every company striving to become the Apple Inc. of the marijuana industry is looking to rear-end the American dreamer before picking his pockets.

Every investment is a gamble, but to keep yourself from getting steamrolled in the business end of the newly organized marijuana trade, it is important to research the fundamentals of a particular company: Who is running the show? What type of company is it? Are they in good standings with the U.S. Securities and Exchange Commission? Are they audited?

To put the legalized marijuana industry into some perspective, here are a few popular companies being traded in the first wave of the marijuana gold rush:

Medical Marijuana Inc. (OTC:MJNA): The largest and most well established company being traded – since April 2009. Currently, stocks are sold at 14 cents each, which is down about 75 percent from where they began.

The company’s portfolio includes, CanChew, which produces a cannabinoid-based gum; PhytoSPHERE Systems, which is focused on developing new technology in growing, packaging and extraction; and KannaLife Sciences, which conducts research to find new healing elements of marijuana.

Investors are encouraged to really dig in to the company’s most recent quarterly report, which was released in June. Unfortunately, MMI does not provide investors with quarterly highlights, so the latest report is the best assessment.

It is worth mentioning that Medical Marijuana Inc. has some nervous investors: “I believe that the shares will be trading in the $0.02 - $0.05 range within the next couple of months, if not sooner,” one investor predicts.

Cannabis Science, Inc. (OTCBB:CBIS): Financial analysts say this company is motivated to do the right thing in regards to medicinal marijuana, but it’s just not a great investment.

The company’s latest report was extremely weak: reporting zero revenue for the quarter ending June 30, with administrative expenditures totaling $533,839. The company also reports that its working capital is in the crapper to the tune of $3 million, which is about a half million dollars more in the hole than a year ago.

Optimistically, even though the company’s 10-Q indicates “There are insufficient liquid assets to meet current liabilities or sustain operations through 2013 and beyond and the Company must raise additional capital to cover the working capital deficit,” Cannabis Science still has a market cap of $27 million, which is one of the highest in the business.

Hemp, Inc. (OTC:HEMP): This company may prove to be a solid investment, but it is important to understand that they deal in hemp products, not marijuana.

The company writes: “The major market for Hemp is as a food or supplement as it is rich in protein, Omega fatty acids and has a high fiber content. Costco carries hemp seeds, and Natural Grocers and Whole Foods Market stock many brands of Hemp food products and supplements. The clothing industry has targeted Hemp as a provocative niche market fabric. High fashion designers Ralph Lauren and Versace make apparel from Hemp blended fabric. Footwear giants Vans and Adidas make Hemp sneakers. Trendy companies market hemp T-shirts, hats, jewelry, backpacks, even pet beds and leashes. Auto manufacturers use durable, green Hemp composites and fabrics when feasible. Industrial Hemp can also be used for building materials, plant based plastics, and paper products.”

Again, this stock may be a worthwhile investment, but it is not the same as a marijuana stock – it will remain basically unaffected by the legalization of recreational or medicinal marijuana.

Growlife, Inc. (OTCBB:PHOT): This company is perhaps one of the most lucrative marijuana investments on the market, because while other companies are deep in the trenches trying to capitalize on the supposed marijuana gold rush, Growlife is simply selling the starry eyed the necessary equipment and tools needed to do their job and make their mark.

The company, which is considered to be a part of the urban gardening industry, does business from retail locations and online stores. Growlife’s most recent income statement shows the company’s total revenue for June 30, 2013 was $865,000, with a profit of $180,000