A company that embraces the internet as the key component in its business. Dotcoms are so named because of the URL customers visit to do business with the company, e.g. www.Amazon.com. The “com” stands for “commercial.” By contrast, websites run by companies whose primary motivations are not commercial, such as nonprofit companies, often have domain names ending in “.org,” which is short for “organization.”
The dotcoms took the world by storm in the late 1990s, rising faster than any industry in recent memory. Despite the fact that most internet companies were losing money at alarming rates, they were given huge valuations on the stock market - but it didn't last for long. The Nasdaq surged to a historical high in March of 2000, and within a few years most of the dotcom sector was wiped out.
Investment dictionary. Academic. 2012.