Here's who's getting rich on Slack's multi-billion dollar IPO

Stewart Butterfield

Slack, the workplace messaging app, is about to go public in a multi-billion IPO.
Some of the company's early investors have stakes worth billions, and many employees have shares worth millions.
Here are the people and investors who stand to make the most.

Slack has released its SEC paperwork to become a public company giving us our first glimpse at its financials and top investors.

As is typical these days, Slack is using a two-tier structure where it will sell Class A shares to the public, with each of those shares offering one vote per share; and it will have Class B shares that come with 10 votes per share.

But Slack's power structure has a twist. Normally the super-voting shares are held by founders as a way to keep tight fisted control after their company goes public. In Slack's case, all of its major shareholders will get the Class B shares that provide 10-votes-per share stock, its current paperwork shows. This includes the company's founders, as well as the major investors, board members at the companies executives (12 executives in all, the paperwork says).

All of those Class B stockholders will do well if the IPO goes well.

We don't know exactly how much money these shareholders stand to make because Slack has not yet priced its Class A shares. We also don't know if the Class B shares will be valued higher/differently. But, we do know that some employees have been allowed to sell their stock on the private, secondary market ahead of the IPO at $28 a share, valuing the company at $17 billion, CNBC reports.

So, just for fun, we used the $28/share price to calculate the value of the stakes owned by its major shareholders. (We'll update these numbers after Slack officially announces the price of its shares.)

With all those caveats, here are the people and investors getting rich from Slack's huge IPO:

Founder CEO Stewart Butterfield

Stewart Butterfield is the CEO co-founder and chairman of Slack.

He previously founded Flickr and sold it to Yahoo, reportedly for around $22 million.

After Flickr, he and his cofounders launched a gaming company and they built their own chat tool to help them work on it. The game never took off, but that chat tool became Slack.

Butterfield is the single largest individual share owner with over 43.2 million shares, or 8.6% of the company. At $28/share his stake would be worth over $1.2 billion.

Founder CTO Cal Henderson

Cal Henderson is the cofounder and CTO of Slack.

He met Butterfield before Flickr was created back when Flickr was also trying to be a gaming company. He helped Butterfield create a photo-sharing service to pay the bills while they worked on the game.

When Butterfield launched another gaming company, Henderson was in. This time they built a wildly successful chat app.

Henderson owns nearly 16.8 million shares. At $28/share his stake would be worth nearly $470 million.

Accel's Andrew Braccia

The success of Slack is a major feather in the cap of Accel partner Andrew Braccia. Braccia invested in Slack during its $1.5 million seed round and bought more shares as the company sold them. (Slack has raised a total of $1.22 billion from venture investors over the years.)

Accel is currently Slack's largest shareholder, with a 24% stake in the company, and it stands to make a lot of profit. It bought series A shares at $2.85 a share, according to Pitchbook.

Accel's owns nearly 120 million shares. At $28/share, that stake would be worth nearly $3.4 billion.

See the rest of the story at Business Insider