Sebastian Siemiatkowski took Klarna from Stockholm to Wall Street
Klarna’s co-founder built “pay later” into a global business, and has been one of the loudest voices on AI at work.
Klarna began in Stockholm in 2005 with a simple idea: let online shoppers pay after their goods arrive. Sebastian Siemiatkowski co-founded the company with Niklas Adalberth and Victor Jacobsson and has been its chief executive from the start.
From invoices to “pay later”
What started as invoice payments in the Nordics grew into a global buy now, pay later business, with Klarna expanding across Europe and into the United States. Its private valuation swung sharply with the market, peaking in 2021 before falling steeply in a 2022 funding round.
In September 2025, Klarna listed its shares on the New York Stock Exchange under the ticker KLAR.
An outspoken AI adopter
Siemiatkowski has been unusually public about using AI inside Klarna, describing how AI tools took on customer service work and how the company slowed hiring as a result. Those comments made Klarna a reference point in the wider debate about AI and jobs.
A hard year for the stock
Klarna’s shares have had a difficult 2026. In August, Siemiatkowski bought about $10 million of Klarna stock through an investment company linked to him, according to a filing. In July, he was inducted into the Swedish Startup Hall of Fame.
What to watch
Consumer credit quality, regulation of buy now, pay later products and Klarna’s push into banking-style services will shape how public investors value the company.
- Company
- Klarna
- Role
- Co-founder & CEO
- HQ
- Stockholm, Sweden
- Founded
- 2005
- Section
- Fintech
This profile draws on public reporting and company materials.
Sources: Finviz: Siemiatkowski share purchase · Realtid: Swedish Startup Hall of Fame · Wikipedia: Klarna
Photo: TechCrunch, CC BY 2.0, via Wikimedia Commons
