If you ask any investor about Initial Public Offerings (IPOs), you’re not likely to get an extreme range of opinions.
That’s because IPOs have been around for centuries, they’re heavily regulated, and they usually are reserved for companies with impressive traction as they transition to the public market through a storied exchange like the NYSE or Nasdaq.
During times of extreme market froth, like the Dotcom bubble, a newly public company can be the subject of intense amounts of speculation. However, in relative terms, most IPOs are fairly benign.
Companies going public simply have a very abbreviated track record, which makes them difficult to value by the market.
At the most basic level, an ICO is a crowdfunded offering of a newly issued cryptocurrency that can be used as a source of capital for startup companies. Investors buy these coins or tokens with legal tender or through the exchange of other cryptocurrencies such as Bitcoin or Ethereum.
Source: http://www.visualcapitalist.com/the-rise-of-the-ico/