OpenAI raises $15 billion at $1.25 trillion valuation, CNBC reports

The first sale of a private company's shares to the public, after which the shares trade on a stock exchange.

An IPO raises money for the company and lets early owners and investors sell part of their stake.

Computer systems that perform tasks that normally require human intelligence, such as understanding language, recognising images or making decisions.

AI is changing work, media and public services, raising questions about jobs, safety and regulation.

A digital currency secured by cryptography and recorded on a blockchain, without a central bank issuing it.

Crypto prices are volatile, and governments are still deciding how to regulate it.