As of Jan. 1, marijuana could be legally purchased and possessed in the state of Colorado. This change in law, however, has failed to win over at least one group of businesses.

Because the substance remains illegal under federal law, banks such as Bank of America (BAC -0.21%) and Wells Fargo (WFC -0.03%) are refusing to provide them with financial products (loans, checking accounts, etc.) for fear of running afoul of federal money laundering rules. In the following video, Fool contributor John Maxfield, the author of a recent in-depth series on the industry, discusses what this means for the business going forward.