United States · Series D startup

Who invested in Stack Exchange

4 rounds we have observed, with the 15 investors named in them. Every figure came from a named source, and where the company reported a raise to the SEC itself, that is shown beside it.

Funding summaryUpdated 26 Oct 2026

$68Mraised across 4 rounds since 2010, from 4 sources

$6.0MSeries A$12MSeries B$10MSeries C$40MSeries D
Latest round
Series D, $40MJan 2015
Step-upi
4×
Investors
15
See who backed them

The funding story

Each circle is a round, placed by date and sized by amount. The line above is the running total.

20112012201320142015
$6.0MSeries A$12MSeries B$10MSeries C$40MSeries D
First round
Series A, $6.0M
May 2010
Biggest round
$40M
Series D · Jan 2015
Usual gap between rounds
22 months
the median of 3

The rounds

  1. Jan 2015
    Series D$40M1 new4 returning

    From a historical funding recordSEC filing: $40M sold, first sale Jan 2015

  2. Jan 2013
    Series C$10M1 new

    From a historical funding record

  3. Mar 2011
    Series B$12M2 new1 returning

    Reported by techcrunch.comSEC filing: $12M sold, first sale Feb 2011

  4. May 2010
    Series A$6.0M11 new

    Reported by readwriteweb.com

Who was in which round

The busiest backers across the latest rounds. A filled square is a round they joined; a dark one, a round they led.

Series A2010Series B2011Series C2013Series D2015Union Square VenturesIndex VenturesSpark CapitalBezos ExpeditionsAndreessen HorowitzFounder CollectiveNaval RavikantRon ConwayHubSpot VenturesJoshua Schachter

Everyone who backed them

Union Square VenturesVC firm3rounds
Index VenturesVC firm2rounds
Spark CapitalVC firm2rounds
Bezos ExpeditionsFamily office2rounds
Andreessen HorowitzVC firm1round
Founder CollectiveVC firm1round
Naval RavikantVC firm1round
Ron ConwayAngel1round
HubSpot VenturesCorporate VC1round
Joshua SchachterVC firm1round
Chris DixonVC firm1round
Bob PaskerAngel1round
Caterina FakeVC firm1round
Nirav ToliaAngel1round
Micah Siegelno record of our own yet1round

Missing a round, or an investor who was in one? Tell us.

Quick answers about Stack Exchange

Who invested in Stack Exchange?

Stack Exchange's investors include Union Square Ventures, Index Ventures, Spark Capital, Bezos Expeditions and Andreessen Horowitz, and 10 more on record.

How much has Stack Exchange raised?

Stack Exchange has raised $68M across 4 rounds since 2010.

When did Stack Exchange last raise?

Stack Exchange's most recent round was a Series D of $40M in Jan 2015.

What was Stack Exchange's biggest round?

Its most recent round, $40M in Jan 2015, is also its largest on record.

Who backed Stack Exchange first?

Stack Exchange's first round on record, in May 2010, was backed by Founder Collective, Union Square Ventures and Naval Ravikant and 8 others.

What stage is Stack Exchange at?

Stack Exchange's latest named round is a Series D, in Jan 2015.

Where is Stack Exchange based?

Stack Exchange is based in the United States.

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