Rocket Fuel nearly doubled on its first day of trading, and investors who bought at the offering later lost most of their money. The company used software to buy online ads. Its systems weighed many signals about each ad slot and decided in real time whether to bid. Advertisers paid it to run campaigns that hit their goals. When it filed to go public in 2013, automated ad buying was growing fast, and so was Rocket Fuel.

Yahoo Alumni and Algorithms

George John, Richard Frankel and Abhinav Gupta founded Rocket Fuel in 2008. Several of the founders had worked at Yahoo. They believed artificial intelligence could buy ads far more efficiently than people working by hand. Their bet was that better algorithms would win the most valuable ad spending. A rocket theme ran through the company's offices and brand. It grew fast.

Sold to Sizmek

Rocket Fuel priced at $29 a share in September 2013 and nearly doubled on its first day. Over the next few years the stock fell as competition grew and margins shrank. Its 2014 purchase of [x+1] added debt and complexity. In 2017 Sizmek bought Rocket Fuel for about $145 million, and offering-day buyers were left with a small part of what they paid. Sizmek itself filed for bankruptcy in 2019.

Cover: Fireworks at Ryogoku (Ryogoku hanabi), from the series "Reflections on Water at Famous Places in Edo (Edo meisho mizu no omokage)", Utagawa Hiroshige. Art Institute of Chicago, public domain. Chosen for fireworks over the river (rocket fuel).