Earlier this month Bank of America Merrill Lynch put out a research report on the marijuana industry’s prospects. Touted as the first such assessment by a major financial institution, the report is a milestone in a fast-growing sector that is hungry for mainstream recognition and the money that comes with it. But a close reading of the report makes clear that marijuana has a long way to go before it resembles a normal American industry.

Twenty-three states currently allow some form of legal marijuana and voters in four states and Washington, D.C., have voted to allow recreational use. Next election day, California and between five and 10 other states are likely to vote on recreational legalization.

In 2014, legal marijuana was the fastest growing industry in the country, grossing $2.7 billion and all signs indicate that it will notch strong growth again this year. The report suggests that it could reach $35 billion by 2020. For comparison, the U.S. pet industry does about $60 billion a year in sales.

But legal marijuana it is not yet a major American industry; only a small fraction of the growers, manufacturers, and sellers have a presence in more than one state.

The report, called “Medical Cannabis has high POTential: A joint biotech and tools Primer” does weed the favor of taking it seriously. It focuses primarily on the medical side with sections devoted to the possibility of cannabis-derived drugs to treat a wide range of illnesses including schizophrenia, type II diabetes, post-traumatic stress disorders and even types of cancer. Among cannabis advocates it’s widely believed that the plant has many as of yet untapped health benefits. The report considers them in the context of pharmaceuticals that could be approved through the established and rigorous FDA process.

“The good news out of all this is it just opens [Wall Street’s] eyes to an investment scene that they may not even appreciate yet,” said Alan Brochstein, an analyst whose businesses 420 Investor and New Cannabis Ventures focus on the intersection of the green industry and finance. However, he adds that the report lacks “actionable information” that might lead a money manager to buy some stock. (None of the report’s authors agreed to be interviewed for this story.)

The most conventional “pure-play” cannabis stock might be GW Pharmaceuticals, a U.K.-based company traded on the Nasdaq. Its drug, Sativex has been approved in more than 20 countries and has launched in the U.K., Germany, Spain, and elsewhere for MS symptoms. The company is exploring other applications for the drug as well.

Like many biotech companies, GW’s value hinges on whether it can get a drug approved by the Food and Drug Administration. It is developing a drug called Epidiolex to treat severe childhood-seizure disorders. Cannabidiol (CBD) a chemical found in marijuana has received high-profile media attention, notably on CNN as a miracle treatment for these devastating diseases, but officially the FDA doesn’t recognize that marijuana has any medical value.

GW currently trades for about $70 and Brochstein estimates that its value, depending on the result of the opaque approval process, which could come in about a year, could swing the stock as high as $180 or as low as $25. It is not a more conventional bet that legal marijuana could soon be broadly available in this country.

There are, no doubt, many who’d like to make that investment and one of the Bank of America report’s takeaways is that such a bet is not available.

Only a few large American companies have openly joined the industry. Of the one’s that have, Brochstein says their profits from marijuana remain small compared to the rest of their business.

One of the only mainstream companies that appears at cannabis-industry conventions is Massachusetts-based Waters Corporation, a maker of chromatography, mass spectrometry, and other scientific equipment used in testing cannabis for contaminants and potency. The report is “bullish” on marijuana testing, ironic for an industry that continues to operate underground.

The situation is similar with the gardening company Scott’s Miracle-Gro. It acquired General Hydroponics, which sells equipment that can be used to grow pot, and a soil company this year for a reported $130 million, but it’s hardly a marijuana company. Many private cannabis companies are eager for investments but with a few exceptions, institutional money has steered clear.

The other option for potential cannabis investors are the cannabis companies traded in the lightly regulated and volatile over-the-counter market. Much of Brochstein’s work focuses on these companies that tend to go ignored by Wall Street analysts. On several occasions, he has called companies out for being scams.

In the dollars-and-cents language of Wall Street, the report is generally optimistic about the industry’s prospects. It notes that “Due to rapidly evolving and potentially conflicting legislation enacted on a state-by-state basis, the cannabis-testing industry is subject to disruptive changes.” Indeed, the testing company CannLabs that two sentences earlier it calls a “leading” service provider, went out of business a few weeks before the report came out.