The Fastest-Growing Startup Ever Just Surpassed $500 Million in Annual Revenue. Here's Why It Keeps Growing, According to Its CEO. Anysphere is the startup behind Cursor, a popular AI coding assistant now used by more than half of Fortune 500 companies.

The AI boom has led to fast-growing startups like OpenAI, which raised a record $40 billion at a $300 billion valuation in April, and Perplexity, which processed 780 million user queries last month. However, investors claim that no AI startup has grown as rapidly as Anysphere, the three-year-old company behind popular AI coding assistant Cursor.

In January, Anysphere became the fastest-growing company to hit $100 million in annual revenue, reaching the milestone in 14 months. Cloud security company Wiz, which hit $100 million in revenue in 18 months, held the previous record. Anysphere is the fastest-growing startup of all time, according to its investors.

In the past few months, the startup has kept growing at a rapid pace. Anysphere announced on Thursday that it had exceeded $500 million in annual revenue and raised $900 million. More than a million people use its technology every day, the company stated.

The new funding round gives Anysphere a $9.9 billion valuation. The startup's previous valuation was $2.5 billion in January, per Bloomberg.

Related: This AI Startup Spent $0 on Marketing. Its Revenue Just Hit $200 Million in March.

So what's the secret behind Anysphere's growth? Anysphere CEO Michael Truell told Bloomberg this week that it boils down to "the value" that the company offers. Since its launch, Anysphere's Cursor AI tool has become popular for its ability to finish lines of code and generate new code based on prompts.

Cursor also acts like a spell check for code, automatically correcting errors so that developers save time. It can explain technical concepts and make recommendations to improve code quality.

"I think a lot of the excitement comes from the value that this tech is giving to developers," Truell told Bloomberg.

Cursor is one tool developers are using to "vibe code," or to prompt AI into writing code instead of writing it out manually. Google CEO Sundar Pichai said earlier this week that he used Cursor to help "vibe code" a webpage.

Related: 'The Coolest Piece of Technology the World Has Ever Seen': OpenAI Is Acquiring Former Apple Designer Jony Ive's Startup for $6.4 Billion

Anysphere makes most of its revenue from Cursor subscriptions, which range from $20 a month for a pro account to $40 per user per month for a business account. Cursor also has a free tier, which includes a two-week trial of its pro plan and up to 200 code completions a month.

Paying individuals made up most of Anysphere's revenue until recently, when the balance shifted to businesses. Late last year, the startup hired its first salespeople to market its technology to enterprises, and the effort has paid off. More than half of Fortune 500 companies are now using Cursor in some capacity, according to Bloomberg.

Cursor isn't the only coding assistant available, competing with billion-dollar startup Replit and the $3 billion startup Windsurf, but it differentiates itself from competitors with its familiar appearance. Cursor resembles Microsoft's code editor, Visual Studio Code, which is used by approximately three out of four developers worldwide.

Related: 'Building It Ourselves': Morgan Stanley Created an AI Tool to Fix the Most Annoying Part of Coding. Here's How It Works.

With the $900 million it has raised, Anysphere wants to keep improving Cursor and bringing value to its customers.

"We want to be the ones pushing the frontier," Truell told Bloomberg.