It is the first time a mainstream institutional investor has publicly put money into cannabis start-up companies.
Other Silicon Valley financiers who had feared bad publicity, or that their money would go up in smoke, are likely to follow suit. The US states of Colorado and Washington became the first to legalise cannabis for recreational use in 2012, with the first shops opening there last year. Colorado is now selling US$30 million of the drug a month, much of it to "drug tourists".
In 2014, Oregon and Alaska also voted to legalise cannabis for recreational use. Votes in six more states, including California, may take place in 2016. There are 23 states that allow the use of cannabis for medical purposes.
However, a revolt is under way. Nebraska and Oklahoma are suing their neighbour Colorado in the Supreme Court, claiming that they have been inundated with cannabis arriving from across their borders. The states claim that the cannabis legalisation violates the US Constitution and accuse Colorado of creating a "dangerous gap in the federal drug control system".
The Silicon Valley cash injection is going to Privateer Holdings, which owns Marley Natural and Leafly.
Its chief executive, Brendan Kennedy, who was educated at Yale, said: "Six to 12 months from now there will be investment banks who will have analysts following cannabis like they follow healthcare or agricultural commodities."
Taylor West, the deputy director of the National Cannabis Industry Association, said: "This is a milestone. It shows the industry is solid enough that an investment firm like this is comfortable stepping in."
-Telegraph Group Ltd