Karl Siebrecht
Angel investor in Seattle
Seattle, Washington
Karl Siebrecht, Angel investor in Seattle 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
AdReadyHow to reach Karl Siebrecht
Angels and operators like Karl Siebrecht reply to specific, personalized notes that show real traction, not mass blasts. Build a verified list, write a note that fits their thesis, and track replies, all on Round Funded.
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About this profile
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Cite this page
Round Funded. "Karl Siebrecht." Round Funded investor database, updated September 8, 2026.
Stable URL, it will not change: https://www.roundfunded.com/en/investor/karl-siebrecht
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.
What stage does Karl Siebrecht invest at?
Karl Siebrecht typically invests at Early Stage Venture. Lead with traction that fits the stage when you reach out.
What is Karl Siebrecht's typical check size?
Karl Siebrecht typically writes checks around $500K. Use it as a signal for whether your raise fits their stage.
How do founders reach investors like this?
Round Funded lists active investors with verified, professional contact details for signed-up founders. Filter by sector, stage and location, then send a personalized pitch from your own inbox.
What is Round Funded?
Round Funded is an investor database and outreach platform for startup founders. It lists 60,000+ active investors with verified contacts, filtered to recent investment activity, and lets founders send personalized pitches from their own Gmail, track replies, and share a free Data Room. Round+ starts at $99 per month with a 3-day trial.