South Street Securities

South Street Securities

South Street Securities was established in March 2001, when the former management team of Citibank's Primary Dealer, Structured Finance, and Repo Finance businesses spun out following the merger of Citi and Travelers Insurance. The firm's founding thesis was to create an independent repo and securities finance dealer, launching with deep institutional fixed-income expertise. It has since expanded its footprint to include a UK representative office and a network of more than 500 financial services counterparties. The firm operates four principal service lines. The Repo Team sources liquidity as a Tier 1 member of the FICC with full netting rights, offering investors participation in the repurchase agreement market. The Mortgage Trading desk provides pipeline hedging for originators, augmented in 2024 by a proprietary TBA trading app. The GX2 Algo Execution business, acquired in 2024, delivers algorithmic execution for U.S. Treasuries and listed derivatives. Warehouse Repo supplies agency mortgage warehouse financing. In 2022, BlackRock and BC Partners provided $90 million in capital, signaling institutional backing for the firm's growth. Headquartered in New York with a London representative office, the firm counts over 115 professionals globally. It has strategically invested in a constellation of affiliated companies: AmeriVet Securities, a service-disabled veteran-owned institutional broker-dealer; fintech service bureau Matrix Applications; and residential loan exchange Maxex, where it announced a liquidity partnership in 2023. The 2022 investment in Digital Prime Technologies and Kayenta Ltd. extended its reach into prime brokerage infrastructure and hedge fund treasury software. It also houses South Street Capital Management, an asset manager formed in 2018 to target residential mortgage-backed securities. South Street operates not as a family office but as a capital-markets boutique with a conglomerate structure of affiliated fintech and broker-dealer subsidiaries. The leadership remains anchored by the original Citibank alumni, with the firm servicing over 500 institutional counterparties from a single, interlocking platform — combining principal trading, agency execution, technology solutions, and exchange infrastructure.