Citadel Securities

Global electronic market maker known for quantitative trading, retail execution and liquidity across equities, options, fixed income and FX.

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Highlights

Founded 2002

Founded by Ken Griffin as a market-making business.

#1 U.S. retail market maker

Executes approximately 35% of all U.S.-listed retail volume.

~30% U.S. listed-options market share

The largest on-exchange options market maker.

~62% of NYSE listings

Citadel Securities is the NYSE's leading designated market maker and has served more than 2,000 listings.

>80% of NYSE IPOs

Selected by corporate issuers for more than 80% of NYSE initial public offerings.

1,600 global clients in 50 countries and jurisdictions

Client coverage includes institutions, central banks, sovereign wealth funds and corporations.

About Citadel Securities

Founded in 2002 by Ken Griffin, Citadel Securities is a market-making firm distinct from the Citadel hedge fund. Peng Zhao, who joined in 2006 as a quantitative researcher, has been CEO since 2017.

The firm provides liquidity and execution to retail and institutional clients across equities, options, fixed income and foreign exchange. Its technology and quantitative research teams continuously price securities, manage trading risk and operate electronic markets at scale.

Citadel Securities is particularly strong in U.S. retail trading, listed options and exchange market making. It is also the designated market maker for a large share of NYSE listings and supports clients through a mix of automated trading, predictive analytics and human market expertise.

Current openings

1 live · 3 total

Trading & Quant Internship 2027

Summer · UK

Open

Rolling

Quantitative Trading - Intern

Summer · UK

Closed

27 Jan 26 closed

EMEA Quant Invitational

Summer · UK

Closed

6 Mar 26 closed

Sources

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