Not long ago, we started a series of posts on our social media about the venture capital success of big companies, now known to everyone.
Such stories help to better understand the meaning of venture capital investment and the potential that lies in early-stage start-ups. Today, we are sharing another story: the Slack venture success story.
Slack, a cloud-based communication and collaboration platform, was founded in 2013 by Stewart Butterfield, Eric Costello, Cal Henderson, and Serguei Mourachov. The platform quickly gained popularity, and by 2014, Slack had raised $12 million in a Series A funding round led by Accel and including participation from Andreessen Horowitz, Spark Capital, and others.
Slack continued to raise significant amounts of funding over the next few years, including a $160 million Series E round in April 2018, which brought the company's valuation to $7.1 billion. In total, Slack raised $1.4 billion in venture capital funding across multiple funding rounds from a variety of investors.
Here's a breakdown of Slack's funding rounds and the investors that participated in each round:
One of Slack's earliest investors was Accel, which participated in the company's Series A funding round with a $7.3 million investment. At the time of Slack's direct listing in 2019, Accel's investment was worth approximately $4.2 billion, representing a return of approximately 575 times its original investment.
Another early investor was Index Ventures, which also participated in Slack's Series A funding round with an $11.8 million investment. At the time of Slack's direct listing, Index Ventures' investment was worth approximately $2.2 billion, representing a return of approximately 187 times its original investment.
Slack's successful public debut on the NYSE in 2019 delivered significant returns for its early investors. The stock opened at $38.50 per share, significantly higher than the reference price set by the NYSE of $26 per share, and the stock price continued to climb throughout the day, closing at $38.62 per share, giving the company a market capitalization of over $23 billion.
Such stories help to better understand the meaning of venture capital investment and the potential that lies in early-stage start-ups. Today, we are sharing another story: the Slack venture success story.
Slack, a cloud-based communication and collaboration platform, was founded in 2013 by Stewart Butterfield, Eric Costello, Cal Henderson, and Serguei Mourachov. The platform quickly gained popularity, and by 2014, Slack had raised $12 million in a Series A funding round led by Accel and including participation from Andreessen Horowitz, Spark Capital, and others.
Slack continued to raise significant amounts of funding over the next few years, including a $160 million Series E round in April 2018, which brought the company's valuation to $7.1 billion. In total, Slack raised $1.4 billion in venture capital funding across multiple funding rounds from a variety of investors.
Here's a breakdown of Slack's funding rounds and the investors that participated in each round:
- Seed round: $1.5 million in August 2013 from investors including Andreessen Horowitz, Accel, and The Social + Capital Partnership.
- Series A round: $12 million in April 2014 from investors including Accel, Andreessen Horowitz, and Spark Capital.
- Series B round: $42.75 million in October 2014 from investors including Thrive Capital, GGV Capital, and Comcast Ventures.
- Series C round: $160 million in April 2015 from investors including Institutional Venture Partners (IVP), Horizons Ventures, and Index Ventures.
- Series D round: $200 million in April 2016 from investors including Thrive Capital, GGV Capital, and Comcast Ventures.
- Series E round: $250 million in September 2017 from investors including SoftBank Vision Fund, Accel, and Andreessen Horowitz.
- Series E-1 round: $141 million in August 2018 from investors including T. Rowe Price, General Atlantic, and Baillie Gifford.
- Series E-2 round: $427 million in April 2018 from investors including Dragoneer Investment Group, General Atlantic, and T. Rowe Price.
One of Slack's earliest investors was Accel, which participated in the company's Series A funding round with a $7.3 million investment. At the time of Slack's direct listing in 2019, Accel's investment was worth approximately $4.2 billion, representing a return of approximately 575 times its original investment.
Another early investor was Index Ventures, which also participated in Slack's Series A funding round with an $11.8 million investment. At the time of Slack's direct listing, Index Ventures' investment was worth approximately $2.2 billion, representing a return of approximately 187 times its original investment.
Slack's successful public debut on the NYSE in 2019 delivered significant returns for its early investors. The stock opened at $38.50 per share, significantly higher than the reference price set by the NYSE of $26 per share, and the stock price continued to climb throughout the day, closing at $38.62 per share, giving the company a market capitalization of over $23 billion.

Overall, Slack's journey from a messaging app for small teams to a widely adopted communication and collaboration platform was supported by significant venture capital investment, and its successful exit through its IPO delivered significant returns for its early investors.