Karl Siebrecht

Active Investor

CoFounder & CEO at FLEXE

Seattle, Washington

Karl Siebrecht, CoFounder & CEO at FLEXE is an active investor based in Seattle, Washington. This profile covers what Karl Siebrecht backs, at which stage, and how founders can reach out in 2026.

Mr. Karl Siebrecht is a Co-Founder and Board Member of Flexe, where he serves as Chief Executive Officer. He served as Co-Founder and Chairman of EnergySavvy, a SaaS-based solution for energy efficiency management. Prior to this, he served as Chief Executive Officer at AdReady, an adtech company. Prior to founding EnergySavvy and joining AdReady, he served as the President of Atlas at aQuantive until its $6 billion acquisition by Microsoft. Prior to that, he served as Manager at Bain & Company. He spent four years in the United States Navy as a Diving Officer. Mr. Siebrecht earned an MBA with honors from the Amos Tuck School at Dartmouth College and a BA in economics from Duke University.

Investor type: Angel
Stages: Early Stage Venture
Invests in: SaaS & EnterpriseConsumer & RetailE-commerce & D2CClimate & EnergyMobility & LogisticsSupply Chain & Logistics
Location: Seattle, Washington
Typical check: $500K
Past investments: 2

Notable investments

EnergySavvyAdReady

How to reach Karl Siebrecht

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Frequently Asked Questions

What does Karl Siebrecht invest in?

Karl Siebrecht invests in SaaS & Enterprise, Consumer & Retail, E-commerce & D2C and Climate & Energy, typically at Early Stage Venture. Match your sector and stage, then reach out with a personalized pitch.