Amplitude began as a failed voice-texting app. Its founders, Spenser Skates and Curtis Liu, built Sonalight in 2012 to let Android users send texts by speaking. The app never caught on. The analytics tool they built to study it did. Other companies asked for it, and the founders turned it into a business. Amplitude skipped a traditional IPO and joined Nasdaq through a direct listing in September 2021.

The Tool Behind the Flop

Skates and Liu turned their internal tracker into Amplitude. The bet was that product teams, as well as marketers, needed analytics. Amplitude showed which features kept users coming back and where they dropped off. Companies could test a change and measure its effect. Customers paid by subscription. The company grew by adding experiments, customer data tools, and session replay. Its customers ranged from startups to large consumer brands.

A Direct Listing Jump

Amplitude listed on Nasdaq under AMPL on September 28, 2021, through a direct listing with a $35 reference price. It sold no new shares. The stock closed its first day up about 57 percent, lifting the company's value from about $5 billion to more than $7 billion. It later fell far below that level. Amplitude still trades on Nasdaq under AMPL.

Cover: The Breaking Wave, Gustave Le Gray. Art Institute of Chicago, public domain. Chosen for a breaking wave (amplitude).