INTELLIGENCE · PERSON DOSSIER
UPDATED 2026-08-13Sebastian Siemiatkowski
Founders & CEOs
Klarna · Sweden
Net worth
$3.2bn (Forbes, 5 April 2022)
Klarna stake
Approximately 7%
Investment vehicle
Flat Capital AB
Klarna market capitalisation
Roughly $7.5bn (August 2026), against $15.1bn at IPO
Identity & Ownership
Current role
Co-founder and Chief Executive Officer, Klarna
Klarna's own earnings releases style him "Sebastian Siemiatkowski, CEO & Co-Founder of Klarna". He has held the chief executive role since the company was founded in 2005.
Born
3 October 1981
Born in Sweden to Polish parents who had emigrated to Uppsala the previous year. Forbes lists his age as 44.
Nationality
Swedish
Forbes records his citizenship as Sweden. He describes himself as a second-generation immigrant on account of his Polish parentage.
Based
Stockholm, Sweden
Forbes lists Stockholm as his residence. Klarna's operating headquarters remain in Stockholm; the listed parent, Klarna Group plc, is a UK-incorporated company traded in New York.
Education
Stockholm School of Economics (MSc); Katedralskolan, Uppsala
He took a sabbatical from the Stockholm School of Economics to start the company that became Klarna, entering the school's entrepreneurship competition with the original idea.
Listing
New York Stock Exchange, ticker KLAR
Klarna listed on the NYSE on 10 September 2025, in the company's twentieth year.
Tenure as chief executive
2005 to present
Twenty-one years as founder-CEO of the same company, spanning private venture funding, a banking licence, an 85% valuation collapse and a New York listing.
Company scale
119m active consumers and over 1m merchants
Klarna's first-quarter 2026 results: 119 million active consumers (+21% year on year), more than one million merchants (+49%), $33.7bn of gross merchandise volume in the quarter.
Personal Wealth & Holdings
Net worth
$3.2bn (Forbes, 5 April 2022)
This is Forbes's last dated figure, struck near Klarna's private peak. It is badly stale: Klarna's valuation fell 85% three months later and its market capitalisation is now roughly half its IPO level. Treat as historical, not current.
Klarna stake
Approximately 7%
Forbes puts his retained holding at about 7% following the September 2025 listing. Klarna's prospectus describes a holding structure that includes entities he controls plus a class of high-vote shares; the precise figure moves with option exercise and lock-up mechanics.
Investment vehicle
Flat Capital AB
Founded with his wife Nina Siemiatkowski in 2013 and listed in 2021. It exists to let outside shareholders invest alongside the couple's private portfolio, charges no management fee or carried interest, and holds stakes including Klarna and SpaceX.
Klarna market capitalisation
Roughly $7.5bn (August 2026), against $15.1bn at IPO
Klarna's shares priced at $40 and closed their first day at $45.82; they traded around $19 in early August 2026, a fall of more than half from the listing-day market value. Figures from a market-data aggregator, not from the company.
Background
Son of Polish immigrants to Sweden
His parents moved from Poland to Uppsala in 1980. Both were academics who arrived with little and placed heavy emphasis on education. He has said Sweden's home-computer subsidy scheme was what put a machine in the family's house.
Burger King; accounts-receivable factoring sales
Forbes records that he worked at a Burger King in Sweden and later sold accounts-receivable services to small businesses — the job that exposed him to the mechanics of invoicing and deferred payment.
Flipping burgers at a Burger King in Sweden
Forbes: "He met one of his Klarna cofounders while the two were flipping burgers at a Burger King in Sweden." Wikipedia's account of Niklas Adalberth describes the three founders as childhood friends who converged at the Stockholm School of Economics; the two accounts are not necessarily in conflict but they are not identical.
23
He started the company that became Klarna at 23, while on sabbatical from the Stockholm School of Economics, with Niklas Adalberth and Victor Jacobsson.
Jane Walerud, SEK 600,000 for 10%
The Swedish angel investor took a tenth of the company for SEK 600,000 in the early Kreditor period and introduced the founders to the engineers who built the first product.
Richard Branson and Ingvar Kamprad
He has cited the Virgin founder and the founder of IKEA as his early models.
Chairman, SSE Business Lab advisory board (from 2015)
The Stockholm School of Economics announced in July 2015 that he would chair a new advisory board for its incubator, SSE Business Lab, alongside other Swedish founders.
The most outspoken large-company executive on AI displacing workers
He has repeatedly gone further in public than peers on AI and headcount, and has said explicitly that other technology chief executives are softening the message. He also fronts Klarna's regulatory positioning personally rather than delegating it entirely to policy staff.
Never learning to code
Told Newsweek in February 2026: "The only thing I kind of regret in my life is not learning to code and be an engineer."
Notable Coverage
25 items
UK BNPL regulation takes effect, bringing Klarna inside the FCA perimeter
Klarna's head of global policy Luke Seaman said: "The FCA's rules largely formalise what we already do: we run affordability checks, show costs up front and treat customers well."
Klarna applies for a US banking licence
Klarna's PriceRunner wins a $1.97bn antitrust award against Google
Klarna's head of communications and policy Dan Greaves said: "When markets work well, everyone benefits. Consumers get higher quality at lower cost, companies stay focused on serving customers rather than defending position."
Klarna returns to net profit in the first quarter of 2026
Klarna reports its first billion-dollar revenue quarter
Siemiatkowski: "Q4 showed that people want a bank that works for them, not against them... Consumers are moving away from predatory revolving credit and we're building the transparent alternative they deserve."
Klarna faces a US securities class action over its IPO disclosures
A Klarna spokesperson said: "We believe the allegations lack merit."
Klarna publishes an open Agentic Product Protocol to make its catalogue readable by AI agents
Siemiatkowski accuses fellow technology chief executives of sugarcoating AI job losses
Klarna prices its IPO at $40 and lists on the New York Stock Exchange
Siemiatkowski reverses course and rehires human customer service agents
CFPB says it will not prioritise enforcement of its BNPL rule
Klarna wins exclusive rights to power Walmart instalment loans in the US via OnePay
Siemiatkowski says AI can already do every job humans do
Finansinspektionen fines Klarna Bank SEK 500m over anti-money-laundering failings
CFPB rules that BNPL lenders must be treated as credit card providers
Klarna's published position was that credit-card rules are the wrong instrument for BNPL and that the CFPB should have written bespoke rules through notice-and-comment rulemaking.
Klarna urges the CFPB to write bespoke BNPL rules rather than apply credit-card law
Klarna says its AI assistant is doing the work of 700 full-time agents
Siemiatkowski: "We are incredibly excited about this launch, but it also underscores the profound impact on society that AI will have."
Klarna's valuation falls 85% to $6.7bn in an $800m round
Siemiatkowski said it was "a testament to the strength of Klarna's business that, during the steepest drop in global stock markets in over fifty years, investors recognized our strong position".
Siemiatkowski criticised for posting a list of laid-off Klarna employees on LinkedIn
Siemiatkowski said "this list is created by employees themselves, voluntarily, in a great attempt to increase their own visibility towards recruiters", and Klarna said staff had opted in and that he was amplifying an employee-led effort.