New York (CNN Business) Slack, the popular workplace communication platform, has filed confidential paperwork to go public.

On Monday, the company announced it had submitted its registration for a "proposed public listing" with the US Securities and Exchange Commission.

The Wall Street Journal previously reported Slack, like Spotify before it, would go public through a direct listing instead of raising new capital. In April, Spotify listed its existing shares directly on the New York Stock Exchange without having underwriters price out the shares based on anticipated demand.

A direct listing could benefit people who work at Slack because employees and longtime shareholders could sell stock on day one. In the case of a traditional IPO, there is a share lockup period of months before they can sell.

Slack CEO and co-founder Stewart Butterfield is known for saying the company is opportunistic about capitalizing on people's interest in the service -- whether it's from investors wanting to pour money into the company or expanding Slack into new countries.

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