Robotaxi pioneer Waymo has raised another $16 billion to help fuel its ambition for its fleet of self-driving cars to provide rides throughout the world. The fundraising values Waymo at $126 billion.

The appraisal underscores investors’ desire to own a piece of the rapidly expanding robotaxi market, as well as how far Waymo has come since starting as a “moonshot” project within Google 17 years ago. 

The new valuation may feed recurring speculation that Waymo will eventually pursue an initial public offering as part of a spinoff from corporate parent Alphabet Inc, which also owns Google.

Alphabet, which boasts a market value of nearly $4.2 trillion, led the fundraising that also included an array of prominent venture capitalists and investment funds.

In a blog post, Waymo said it plans to use the the money to extend its reach beyond the six metropolitan areas where its robotaxis already give rides in California, Arizona, Georgia, Texas and Florida. It’s gearing up to enter more than 20 other cities, including London and Tokyo. Waymo’s robotaxis already provide more than 400,000 weekly rides.

“We are positioned to move forward with unprecedented velocity, while maintaining our industry-leading safety standards,” Waymo said in the post.

Although Waymo’s robotaxis have so far compiled a mostly clean driving record, they have experienced various problems that have triggered community backlashes and regulatory inquiries.

Last year in San Francisco, a Waymo robotaxi ran over and killed a 9-year-old cat beloved around its neighborhood. Many of the self-driving vehicles later contributed to traffic chaos during an extended power outage when they stalled out at intersections with darkened traffic signals. The National Transportation Safety Board is also investigating complaints in Austin, Texas, about Waymo robotaxis operating unsafely around school buses carrying children.

Waymo is gearing up for more competition from Amazon-backed Zoox in San Francisco and Tesla as it continues to pursue CEO Elon Musk’s promise to build a network of robotaxis throughout the U.S.

– The Associated Press contributed to this article.