It all started in 2013 when software engineer J.R. Willett wrote a white paper titled "The Second Bitcoin White Paper" for MasterCoin (which later rebranded to Omni Layer), raising US$600,000 for the project.
By 2014, seven projects had raised a total of US$30 million. The largest that year was Ethereum, which raised over US$18 million by selling 50 million ETH to the public.
2015 was a quieter year. Seven ICOs raised a total of US$9 million, with the largest, Augur, collecting just over US$5 million.
Activity started to pick up in 2016 when 43 ICOs, including Waves, Iconomi, Golem, and Lisk, raised US$256 million. It was during this period that the DAO project, an autonomous investment fund that aimed to encourage Ethereum ecosystem development by allowing investors to vote on projects to fund, launched its ICO. Not long after the sale raised a record US$150 million, a hacker siphoned off approximately US$60 million worth of ETH, leading to the project's collapse and a hard fork of the Ethereum protocol.
The DAO's failure did not deter the increasing enthusiasm for the nascent digital asset space. In December, the first fund dedicated to ICO investment received significant backing from old-school venture capitalists.
Partially driven by technological advancements, 2017 saw ICOs reach a new zenith, with 342 ICOs raising around US$5.4 billion and thrusting the concept to the forefront of blockchain innovation.