South Street Securities Holdings, Inc.

What South Street Securities Holdings, Inc. does

South Street Securities Holdings, Inc. is a privately held, New York-based diversified financial services and technology holding company founded in 2000. Its core operating subsidiary, South Street Securities LLC, is a FINRA, SIPC, NFA, OCC and Tier 1 FICC member broker-dealer that provides repo dealer financing (US Treasuries, Agency MBS), TBA mortgage origination hedging, warehouse repo, securities lending and equity finance, and algorithmic trade execution to institutional clients including hedge funds and traditional asset managers, REITs, tri-party investors, mortgage lenders, mid-market broker-dealers, and corporate and government issuers. The firm operates with a relationship-driven direct sales model and earns transaction-based revenue on repo, securities lending, and algo execution, plus managed-service revenue from technology and back-office services.

The platform is built around a proprietary technology stack: the GX2 ExMode hosted execution platform for multi-product, multi-asset spread execution without legging risk; GX2 STAR for smart order routing across treasury markets; and Matrix Applications' collateral management, margining and clearing systems for institutional fixed income and equities securities lending. In 2024 South Street acquired GX2 Systems and its broker-dealer subsidiary (consolidated into South Street Securities LLC in 2025) and in 2026 acquired Lime Funding LLC, an asset-backed commercial paper conduit. Affiliates include AmeriVet Securities (SDVOB broker-dealer), Matrix Applications (fintech service bureau), GX2 Systems, MAXEX (residential loan exchange), South Street Capital Management, South Street U.K./EMEA, and an investment in Digital Prime Technologies (digital asset prime brokerage). Capital partners include Atlas Merchant Capital (Bob Diamond) and BlackRock/BC Partners.

Name

South Street Securities Holdings, Inc.

Legal name

South Street Securities LLC

Website

https://southstreetsecurities.com

Company type

Private

Founded year

2000

Operating status

Operating

Headcount range

101–250 employees

Short description

South Street Securities Holdings is a private, New York-based financial services holding company. Its core broker-dealer subsidiary provides repo financing, TBA mortgage hedging, securities lending, and algorithmic execution to institutional asset managers, REITs, mortgage lenders, and broker-dealers.

Ownership category

akta.pro rank

Product category

Institutional Broker-Dealer Services

NAICS

Securities and Commodity Contracts Intermediation and Brokerage (5231), Investment Banking and Securities Intermediation (523150), Investment Banking and Securities Intermediation (52315)

SIC

Security Brokers, Dealers & Flotation Companies (6211), Asset-Backed Securities (6189)

akta.pro primary industry

Securities Borrowing & Lending (Equities/Bonds) (FSACAIAC)

akta.pro secondary industries

Stock Borrow/Loan (Equities Securities Lending) (FSACAFAD), Mortgage Loan Sales & Aggregation (Correspondent/Conduit Aggregators) (FSALAFAD), Securitization Administration & Deal Services (Trustee, Custodian, Paying Agent) (FSALAFAK)

Keywords

• Repurchase agreement financing
• Securities lending services
• Mortgage trading services
• Algorithmic trading execution
• Collateral management systems

Headquarters

HQ city

New York

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Infrastructure, Marketing or Sales, Others

Revenue model

1. Repo Dealer Financing: Repo dealer financing services for US Treasuries, Agency MBS, TBA mortgage origination hedging, and equity finance. The company acts as an intermediary in the repurchase agreement market, providing financing solutions to institutional clients.
2. Securities Finance Services: Securities lending and equity finance services including hard-to-borrow specials, matched book trading, and short covering solutions for institutional clients.
3. Algorithmic Trade Execution: GX2 algorithmic execution services for US Treasury and listed derivatives trading, including spread execution and rate-algo technology for outright, spread and basis strategies.
4. Technology and Back-Office Services: Matrix Applications provides technology and back-office services including collateral management systems, margining, clearing, and operational assistance for institutional firms.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

South Street Securities Holdings, Inc. is an institutional financial services holding company whose core broker-dealer subsidiary provides repurchase agreement (repo) financing for US Treasuries and Agency MBS, TBA mortgage origination hedging for mortgage originators, equity finance and securities lending (including hard-to-borrow specials and matched book trading), and algorithmic trade execution for US Treasuries and listed derivatives. Through affiliates Matrix Applications and GX2 Systems, the firm also provides proprietary collateral management technology and electronic trading solutions.

Product overview

South Street Securities Holdings, Inc. operates as a diversified financial services and technology holding company with a platform-plus-affiliates architecture. The core operating entity, South Street Securities LLC, provides repo dealer financing (US Treasuries, Agency MBS), TBA mortgage origination hedging, equity finance, and algorithmic trade execution services. The company has expanded through strategic affiliates including Matrix Applications (collateral management and fintech services), AmeriVet Securities (service-disabled veteran-owned broker-dealer), GX2 Systems (electronic trading solutions for fixed income and futures), and MAXEX (residential mortgage exchange). Recent acquisitions include GX2 Spread Markets (algorithmic execution platform, now consolidated) and Lime Funding LLC (asset-backed commercial paper conduit). The portfolio is unified under common ownership with shared distribution, risk management, and technology capabilities.

Differentiator

Problem solved

Functional benefit

Brands

• GX2 Algo Execution: Algorithmic execution services for U.S. Treasury and listed derivatives trading.
• Repo Services
• Mortgage Trading
• Warehouse Repo
• TBA Trading App

Products and services

• Repo Services Repo Team offers one of the safest methods for institutional investors to participate in the Repurchase Agreement market, providing repo cash investment and repo security financing services for US Treasuries and Agency MBS, with full repo netting rights through Tier 1 FICC membership.
• Mortgage Trading Mortgage Trading team provides access for Mortgage Originators to hedge their forward pipeline exposure through TBA (To Be Announced) mortgage trading services.
• GX2 Algo Execution GX2 Algo Execution Team delivers advanced algorithmic execution for U.S. Treasury and listed derivatives trading, including spread execution, market aggregation, and algorithmic strategy execution services.
• Warehouse Repo Warehouse Repo Team provides agency mortgage warehouse financing for mortgage lenders.
• TBA Trading App Cross-platform (iOS, Android, desktop) application that allows mortgage originator customers to access live TBA trading with South Street's TBA Desk, view specified bond market color, track transaction history, and communicate with the trading team via real-time chat.
• Lime Funding LLC - Asset-Backed Commercial Paper Conduit An asset-backed commercial paper conduit that provides loans to corporate and institutional borrowers, with funding raised through ABCP issuance to investors, integrated into South Street's securities finance platform following acquisition.

Named customers6 records

Segments6 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration1 record

Feature4 records

Partnerships

Eight partnerships are on record, tiered minor and core.

• Fiver Children's FoundationminorOthers · 14 May 2026Partnership with Fiver Children's Foundation for youth development programs. Donald Webbe awarded Richard Adams Leadership Award at the foundation's 2026 Annual Benefit which raised more than $1.5 million.
• Lime Funding LLCcoreStrategic or Co-development Partner · 28 February 2026Acquisition of 100% equity interest in Lime Funding LLC, an asset-backed commercial paper conduit that provides loans to corporate and institutional borrowers, with funding raised through ABCP issuance. The acquisition integrates Lime Funding into South Street's securities finance platform, combining distribution and risk management with GreensLedge Advisors' conduit expertise and Sumitomo Mitsui Trust Bank's liquidity support.
• GX2 Systems LLCcoreStrategic or Co-development Partner · 16 January 2024Acquisition of GX2 Systems LLC, including its broker-dealer subsidiary GX2 Spread Markets. The acquisition enhances South Street's capabilities in securities financing, processing, execution, and analytics through GX2's innovative trading technology and client network. GX2 Systems engineers electronic trading solutions for fixed income and futures markets.
• EvertreencoreStrategic or Co-development Partner · 6 May 2022Partnership with Evertreen, an online platform for tree planting and carbon offsetting. South Street has committed to planting trees to offset carbon footprint, with over 11,000 trees planted across Honduras, Kenya, Madagascar, Brazil, and the UK since 2022. The partnership includes satellite tracking of tree growth and creates working hours for local farming communities.
• Digital Prime TechnologiescoreStrategic or Co-development Partner · 27 April 2022Investment and partnership in Digital Prime Technologies, an innovative provider of turnkey prime brokerage solutions for digital assets. The partnership allows South Street to expand into digital asset trading and lending space with institutional clients. Digital Prime's platform enables traditional securities-based prime brokers to offer digital asset execution, leverage, and financing capabilities.
• KayentaminorStrategic or Co-development Partner · 25 March 2022Lead investor in Kayenta's capital raise. Kayenta develops cloud native, API-driven software for hedge funds providing transparency into financing costs. The partnership complements South Street's existing business and expands FinTech footprint.
• Sunrise Day CampminorOthersPartnership with Lucille and Jay Chazanoff Sunrise Day Camp of Staten Island, a free summer camp program for children with cancer and their siblings. South Street hosted annual toy drive and donated 180+ toys.
• CellTrustminorOthersText messaging vendor providing CellTrust SL2 platform for communicating with individuals in relation to business relationships in compliance with applicable laws and regulations.

Scale indicators5 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Virtu Financial: Virtu Financial is a leading electronic market maker and execution services provider across global equities, fixed income, and ETFs. Its algorithmic execution and smart order routing capabilities directly overlap with GX2's ExMode and STAR offerings.
• Cantor Fitzgerald: Cantor Fitzgerald operates a large fixed income, repo, and equity finance franchise through its broker-dealer and BGC Group affiliates. Direct overlap with South Street on repo financing, securities lending, and mortgage-related products makes it a close functional peer.
• Marex: Marex is a diversified financial services platform offering execution, clearing, and market-making across commodities, fixed income, and equities, including securities finance. Its institutional focus and multi-asset intermediation model are highly comparable to South Street's platform-plus-affiliates architecture.
• Piper Sandler: Piper Sandler is a mid-market institutional broker-dealer with active fixed income, public finance, and mortgage trading businesses. It served as lead manager on South Street's 2022 senior unsecured notes and competes in adjacent institutional capital markets activities.
• StoneX Group: StoneX operates a global institutional broker-dealer and securities finance franchise spanning fixed income, equities, commodities, and securities lending. Its diversified intermediary model closely mirrors South Street's repo, mortgage hedging, and securities lending stack.
• EquiLend: EquiLend is a leading securities finance technology and trading platform serving institutional lenders and borrowers globally. It is a direct comparable to South Street's Matrix Applications and securities finance business, and is also named as a Digital Prime Technologies partner.

Emerging players

• Greystone: Greystone is a commercial real estate finance and advisory firm with an asset-backed commercial paper conduit (Greystone Funding). It is a comparable to South Street's Lime Funding acquisition for institutional ABCP issuance and conduit management.

Broad incumbents

• State Street: State Street is a major repo dealer and securities services provider with global agency lending and collateral management offerings. As a broad incumbent, it competes for the same institutional cash and securities financing mandates South Street targets.
• Tradeweb Markets: Tradeweb operates electronic marketplaces for fixed income, derivatives, and ETFs, including treasury and repo execution. As a broad incumbent in electronic fixed income trading, it competes with GX2's algo execution and aggregation capabilities.
• BNY Mellon: BNY Mellon is a global primary dealer and tri-party repo agent with a deep agency securities finance and collateral management franchise. While vastly larger, its repo and securities lending businesses compete directly with South Street's core activities.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks7 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/south-street-securities-llc

Compliance7 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Subsidiaries8 records

Funding overview

Funding rounds5 records

Investors3 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A1 record

Investments2 records

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about South Street Securities Holdings, Inc.