The cool kids like to say the last mile of inflation is the toughest to fight.

It must be true.

Everyone says it's true, but is it?

I'm David Brancaccio in New York.

First, what is a company worth if its tech is in nearly every mobile phone on Earth?

Today, the market gave us the answer, $55 billion.

That's the valuation of Chip Designer Arm, a company centered in Britain, based on its

initial public offering of stock.

That's the year's biggest IPO so far, Marketplace's Nova Sofo, has more.

The Japanese Investment firm SoftBank, which owns Arm, raised nearly $5 billion through

its initial public offering, while hanging onto about 90% of the chipmakers shares.

Many of Arm's biggest clients have reportedly signed up as investors, including Apple,

Alphabet, and Samsung.

Arm designs the architecture for building chips, especially those used in mobile devices.

The company makes most of its money through licensing fees.

You'd think there would be no question about its value, but investors did have questions,

because the mobile phone market is saturated.

How much growth would there be in the future?

SoftBank pointed toward other emerging technologies, artificial intelligence, and autonomous driving.

SoftBank says the technology that Arm licenses stands to benefit.

I'm Nova Sofo, for Marketplace.

Yesterday, we reported on a spike in inflation up six tenths of a percent in August, a jump

...