New York, NY Office

Gustav Langford is a financial advisor with Siebert AdvisorNXT, LLC., holding a Series 63 designation and 27 years of industry experience. He has worked at Muriel Siebert & Co., Inc. and Stockcross Financial Services, Inc. Langford volunteers one hour per month at the Elkins Park Firehouse. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through its web-based AdvisorNXT program, using algorithmic portfolio construction based on Modern Portfolio Theory and offering both discretionary and non-discretionary account management.

Marvin Rivas is a financial advisor at Siebert AdvisorNXT, LLC with five years of industry experience. He holds a Series 66 designation and has worked at Siebert AdvisorNXT and Muriel Siebert & Co., Inc. since 2021. Prior to his career in finance, he held positions at XPO Logistics, New Jersey Institute of Technology, CVS Pharmacy, and Elizabeth High School. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through a web-based platform that combines algorithmic portfolio construction with dedicated advisor support. The firm offers both discretionary and non-discretionary account management and integrates strategies such as mean-variance optimization and covered-call transitions.

Zachary Banks is a financial advisor at Siebert AdvisorNXT, LLC with three years of industry experience. He holds a Series 66 designation and has worked at Muriel Siebert & Co., LLC and LPL Financial. Banks divides his time between Siebert AdvisorNXT and Muriel Siebert & Co., both affiliated with Siebert Financial Corporation. Siebert AdvisorNXT provides investment management services primarily to individuals, families, trusts, and business entities through its web-based AdvisorNXT platform. The firm employs an algorithmic approach based on Modern Portfolio Theory to build portfolios of low-cost ETFs and ETNs, offering both discretionary and non-discretionary management along with access to third-party managers and specialty strategies.

Peter Sosnowski is an investment advisor at Siebert AdvisorNXT, LLC with 40 years of industry experience. He holds Series 63 and Series 65 licenses and has spent over two decades at Muriel Siebert & Co., Inc., continuing his work there under its current structure since 2022. He divides his time equally between Siebert AdvisorNXT and Muriel Siebert & Co., LLC, both affiliated entities under Siebert Financial Corporation. Siebert AdvisorNXT primarily serves individuals, including high-net-worth clients, as well as families, trusts, and certain business entities. The firm offers investment management through its AdvisorNXT platform, which employs a risk-tolerance questionnaire and Modern Portfolio Theory to build portfolios of low-cost ETFs and ETNs, supplemented by discretionary and non-discretionary management options and access to third-party managers and specialty strategies.

Mark Malek is an investment advisor representative with Siebert AdvisorNXT, LLC and Muriel Siebert & Co., Inc., holding Series 63 and Series 65 licenses and bringing 15 years of industry experience. His career includes roles at multiple firms, such as Wealthsource Partners, Vellum Financial, Quantitative Insight Partners, and Praxis Insight Advisors. He divides his time between Siebert AdvisorNXT and Muriel Siebert & Co., both affiliates under Siebert Financial Corporation. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through a web-based platform that combines algorithmic portfolio construction with access to dedicated investment advisors. The firm offers discretionary and non-discretionary account management, utilizing strategies such as mean-variance optimization with ETFs and ETNs, and maintains affiliations with in-house broker-dealer and custodial partners.

Kyle Gonzalez is a financial advisor with Siebert AdvisorNXT, LLC., holding a Series 66 license and two years of industry experience. He has been with Muriel Siebert & Co. since 2021, working full time split between Muriel Siebert & Co. and Siebert AdvisorNXT, both under the Siebert Financial Corporation umbrella. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through a web-based platform that combines algorithmic portfolio construction with access to third-party sub-advisors and optional dedicated investment adviser representatives. The firm offers discretionary and non-discretionary management, with notable features including covered-call transition strategies and integration with an affiliated broker-dealer.

Sarah Braddock is an Investment Advisor Representative at Siebert AdvisorNXT, LLC., with nine years of industry experience. She has worked at Searchlight Investments, LLC and Searchlight Financial Advisors since 2016. She divides her time equally between Siebert AdvisorNXT and Muriel Siebert & Co., LLC, both subsidiaries of Siebert Financial Corporation. Siebert AdvisorNXT provides investment management primarily to individuals, families, trusts, and certain business entities, utilizing a web-based wealth management platform and third-party managers. The firm employs an algorithmic implementation of Modern Portfolio Theory to construct portfolios and offers discretionary and non-discretionary management with access to multiple investment strategies.

Gary Gonzalez is a financial advisor with Siebert AdvisorNXT, LLC, holding a Series 66 designation and 24 years of industry experience. He has worked at Muriel Siebert & Co., Inc. since 2018 and previously spent 12 years at Stockcross Financial Services, Inc. Gonzalez splits his time equally between Siebert AdvisorNXT and Muriel Siebert & Co., both under the Siebert Financial Corporation umbrella. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through its web-based AdvisorNXT program and access to third-party sub-advisors. The firm employs mean-variance optimization based on Modern Portfolio Theory, utilizing ETFs and ETNs, and combines algorithmic portfolio construction with dedicated advisor support.

Andrew Mcdonald is an investment advisor representative at Siebert AdvisorNXT, LLC with 42 years of industry experience. He has been with Muriel Siebert & Co., Inc. since 2017 and has concurrently worked at StockCross Financial Services since 2007. Mcdonald holds Series 63 and Series 65 licenses. Outside of his advisory roles, he has established a real estate holdings business, A & C Properties LLC. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through its web-based AdvisorNXT program. The firm utilizes algorithmic portfolio construction based on Modern Portfolio Theory, implemented mainly with ETFs and ETNs, and offers both discretionary and non-discretionary management options.

Donato Cuttone Jr. is a financial advisor at Siebert AdvisorNXT, LLC. He holds Series 63 and Series 65 licenses and has one year of industry experience. Prior to joining Siebert AdvisorNXT, he worked at iHeart Media and served in the U.S. Army. Outside of his advisory role, he is involved with Cuttone Enterprises, LLC. Siebert AdvisorNXT provides investment management primarily to individuals, families, trusts, and certain business entities through its web-based AdvisorNXT platform. The firm combines algorithmic portfolio construction based on Modern Portfolio Theory with access to third-party managers and specialty strategies such as covered-call transitions.

Brett Sonzogni is a financial advisor with Siebert AdvisorNXT, LLC. He holds a Series 66 designation and has eight years of industry experience. His prior roles include positions at Muriel Siebert & Co., Revere Securities LLC, Empower Private Wealth, and B. Riley Wealth Advisors. Outside of finance, he is CEO of Social Sound Club LLC, a music production and entertainment company. Siebert AdvisorNXT provides investment management primarily to individuals, families, trusts, and certain business entities, utilizing a web-based platform that incorporates Modern Portfolio Theory and access to third-party managers. The firm offers both discretionary and non-discretionary portfolio management with a focus on low-cost ETFs, mutual funds, and Independent Managers, alongside specialized strategies such as a covered-call transition approach.

John Moran is a financial advisor at Siebert AdvisorNXT, LLC., holding a Series 66 designation with three years of industry experience. His prior roles include positions at Muriel Siebert and Co. LLC, Millennial Advisers LLC, Allied Millennial Partners, NYLIFE Securities LLC, and New York Life Insurance. Siebert AdvisorNXT provides investment management primarily to individuals, families, trusts, and certain business entities through its AdvisorNXT web-based platform, offering automated portfolio construction based on Modern Portfolio Theory, managed programs including asset allocation and specialty strategies, and access to third-party managers.

Colin Mc Donald is an investment advisor with Siebert AdvisorNXT, LLC, holding Series 65 and Series 63 licenses and possessing four years of industry experience. His prior work includes roles at Muriel Siebert & Co., Inc., Cushman & Wakefield, and CBRE. Outside of advisory services, he is involved in a family real estate business where he manages tenant relations and markets rental units. Siebert AdvisorNXT provides investment management primarily to individuals, families, trusts, and certain business entities through its web-based wealth management platform, incorporating algorithmic portfolio construction and access to third-party managers. The firm offers both discretionary and non-discretionary account management with a focus on low-cost ETFs, mutual funds, and specialty strategies.

Ronald Roberts is a financial advisor with Siebert AdvisorNXT, LLC, holding a Series 63 designation and 36 years of industry experience. He has worked at Muriel Siebert & Co., LLC since 2020 and previously spent 18 years at Stockcross, Inc. Roberts is a dual employee of Siebert AdvisorNXT and Muriel Siebert & Co., LLC, both under the same parent company, Siebert Financial Corporation. Siebert AdvisorNXT provides investment advisory and portfolio management services primarily to individual and high-net-worth clients through a web-based platform that integrates algorithmic portfolio construction with access to third-party sub-advisors. The firm offers discretionary and non-discretionary management options and features strategies such as a covered-call transition plan and a combination of automated portfolios with dedicated human advisor support.

Natasha Howe is an investment advisor representative at Siebert AdvisorNXT, LLC with six years of industry experience. She has worked at Muriel Siebert & Co., Inc. since 2019, splitting her time equally between that firm and Siebert AdvisorNXT, both subsidiaries of Siebert Financial Corporation. Prior to her financial career, she held roles in fitness and nutrition industries. Siebert AdvisorNXT provides investment management services mainly to individuals, families, trusts, and certain business entities through a web-based wealth management platform. The firm employs algorithmic portfolio construction based on Modern Portfolio Theory, offers access to independent managers, and features both discretionary and non-discretionary account management approaches.