Sinclair M. Ridley-thomas

SG AMERICAS SECURITIES

Menlo Park, CA 94025

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CRD#: 6534591

Professional summary

Sinclair Mark Ridley-thomas, who also goes by Sinclair Mark Ridley-thomas, is a registered financial professional currently at SG AMERICAS SECURITIES, LLC located in Menlo Park, California.

Sinclair is registered as a RR (Registered Representative) and started their career in finance in 2015. Sinclair has worked at 7 firms and has passed the Series 63, Series 7TO, SIE and Series 79 exams.

Question & Answer

Are you a "fiduciary"?

Aliases

Sinclair Mark Ridley-Thomas

Other business activities

Outside business activity is any business or activity undertaken by an advisor that is outside the scope of their relationship with their firm (e.g., consulting services, real estate, freelance work, teaching, etc.). Investors should stay informed about these activities to ensure no conflicts of interest.

The advisor shows no other business activity.

Blog Corner

CRS (Client Relationship Summary) - BD

Click below to view Sinclair Mark Ridley-thomas's CRS (Customer Relationship Summary).

Certified licenses

Advisors may have various certifications and credentials from different organizations. AdvisorCheck highlights these seven certifications - AIF®, CFP®, ChFC®, CFA, CLU®, CIMA®, CPWA®

None

Experience

Current

December 3, 2025 - Present

SG AMERICAS SECURITIES, LLC

Office #1: 2882 Sand Hill Road Suite 118, Menlo Park, CA 94025

CRD#: 128351

Menlo Park, CA

Past

September 3, 2024 - December 2, 2025

WEILD & CO.

CRD#: 132398

BOULDER, CO

Past

May 8, 2024 - September 9, 2024

LOOP CAPITAL MARKETS LLC

CRD#: 43098

SAN FRANCISCO, CA

Past

July 19, 2022 - May 13, 2024

UBS SECURITIES LLC

CRD#: 7654

SAN FRANCISCO, CA

Past

December 23, 2020 - June 22, 2022

CITIGROUP GLOBAL MARKETS INC.

CRD#: 7059

SAN FRANCISCO, CA

Past

July 11, 2017 - October 6, 2020

RBC CAPITAL MARKETS, LLC

CRD#: 31194

SAN FRANCISCO, CA

Past

November 4, 2015 - July 5, 2017

CITIZENS JMP SECURITIES, LLC

CRD#: 22208

SAN FRANCISCO, CA

State Registrations and Notice Filings

Listed states reflect where the advisor is authorized to serve clients under state regulations.

indicates the advisor is registered as a Registered Representative in this state, allowing them to offer securities such as stocks, bonds, and mutual funds through a broker-dealer.

Visual representation of state registrations

Alabama
(12/3/2025)

Alaska
(12/3/2025)

Arizona
(12/3/2025)

Arkansas
(12/3/2025)

California
(12/3/2025)

Colorado
(12/3/2025)

Connecticut
(12/3/2025)

Delaware
(12/3/2025)

District of Columbia
(12/3/2025)

Florida
(12/3/2025)

Georgia
(12/3/2025)

Hawaii
(12/3/2025)

Idaho
(12/3/2025)

Illinois
(12/3/2025)

Indiana
(12/3/2025)

Iowa
(12/3/2025)

Kansas
(12/3/2025)

Kentucky
(12/3/2025)

Louisiana
(12/3/2025)

Maine
(12/3/2025)

Maryland
(12/3/2025)

Massachusetts
(12/3/2025)

Michigan
(12/3/2025)

Minnesota
(12/3/2025)

Mississippi
(12/3/2025)

Missouri
(12/3/2025)

Montana
(12/3/2025)

Nebraska
(12/3/2025)

Nevada
(12/3/2025)

New Hampshire
(12/3/2025)

New Jersey
(12/3/2025)

New Mexico
(12/3/2025)

New York
(12/3/2025)

North Carolina
(12/3/2025)

North Dakota
(12/3/2025)

Ohio
(12/3/2025)

Oklahoma
(12/3/2025)

Oregon
(12/3/2025)

Pennsylvania
(12/3/2025)

Puerto Rico
(12/3/2025)

Rhode Island
(12/3/2025)

South Carolina
(12/3/2025)

South Dakota
(12/3/2025)

Tennessee
(12/3/2025)

Texas
(12/3/2025)

Utah
(12/3/2025)

Vermont
(12/3/2025)

Virginia
(12/3/2025)

Washington
(12/3/2025)

West Virginia
(12/3/2025)

Wisconsin
(12/3/2025)

Wyoming
(12/3/2025)

Exams

State Security Law Exam

Series 63

Date: 1/8/2016

Uniform Securities Agent State Law Examination

General Industry/Product Exam

Series 7TO

Date: 6/28/2021

General Securities Representative Examination

General Industry/Product Exam

SIE

Date: 10/1/2018

Securities Industry Essentials Examination

General Industry/Product Exam

Series 79

Date: 11/4/2015

Investment Banking Registered Representative Examination

SRO Registrations

BOX Exchange LLC

SRO Registrations

Cboe BYX Exchange, Inc.

SRO Registrations

Cboe BZX Exchange, Inc.

SRO Registrations

Cboe C2 Exchange, Inc.

SRO Registrations

Cboe EDGA Exchange, Inc.

SRO Registrations

Cboe EDGX Exchange, Inc.

SRO Registrations

Cboe Exchange, Inc.

SRO Registrations

FINRA

SRO Registrations

Investors' Exchange LLC

SRO Registrations

Long-Term Stock Exchange, Inc.

SRO Registrations

MEMX LLC

SRO Registrations

MIAX PEARL, LLC

SRO Registrations

NYSE American LLC

SRO Registrations

NYSE Arca, Inc.

SRO Registrations

NYSE National, Inc.

SRO Registrations

NYSE Texas, Inc.

SRO Registrations

Nasdaq BX, Inc.

SRO Registrations

Nasdaq GEMX, LLC

SRO Registrations

Nasdaq ISE, LLC

SRO Registrations

Nasdaq MRX, LLC

SRO Registrations

Nasdaq PHLX LLC

SRO Registrations

Nasdaq Stock Market

SRO Registrations

New York Stock Exchange

Current Firm

SG AMERICAS SECURITIES, LLC

CRD#: 128351 / SEC#: , 8-66125

Broker-Dealer Firm Regulated by FINRA (New York district office)

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Contact information

Main Address

245 Park Avenue, New York, NY 10167

Mailing Address

245 Park Avenue, New York, NY 10167

Phone number

(212) 278-6000

Established

Delaware since 08/08/2003

Firm type

Limited Liability Company

Fiscal year end

December

Firm Size

Large

# of Employees

FINRA licenses (52 States and Territories)

Documents

Direct owners and executive officers

Name	Position	CRD#
SG AMERICAS SECURITIES HOLDINGS, LLC	DIRECT OWNER
CARTIER, SYLVAIN	CHIEF EXECUTIVE OFFICER	6390499
CULLEN, EDWARD PATRICK	OPERATIONAL RISK MANAGER	1551615
GERLESITS, WILLIAM R	CHIEF COMPLIANCE OFFICER	5457051
O'KEEFE, THOMAS WILLIAM	PRINCIPAL FINANCIAL OFFICER	3054453
ZIELINSKI, GREGORY W	CHIEF OPERATING OFFICER	2384242

Disclosures

Regulatory Event	114
Criminal	1
Arbitration	1

Red Flags

Disclosures can be potential red flags, including customer disputes, regulatory fines, employer terminations, bankruptcies, judgments, liens, or certain criminal activities.

Check for any disclosures as part of your thorough research when choosing an advisor.

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Advisor Monitoring

Firm Stability Insights

Sinclair M. Ridley-thomas

Professional summary

Question & Answer

Aliases

Other business activities

Blog Corner

CRS (Client Relationship Summary) - BD

Click below to view Sinclair Mark Ridley-thomas's CRS (Customer Relationship Summary).

Certified licenses

Experience

WEILD & CO.

LOOP CAPITAL MARKETS LLC

UBS SECURITIES LLC

CITIGROUP GLOBAL MARKETS INC.

RBC CAPITAL MARKETS, LLC

CITIZENS JMP SECURITIES, LLC

State Registrations and Notice Filings

Exams

Series 63

Date: 1/8/2016

Series 7TO

Date: 6/28/2021

SIE

Date: 10/1/2018

Series 79

Date: 11/4/2015

BOX Exchange LLC

Cboe BYX Exchange, Inc.

Cboe BZX Exchange, Inc.

Cboe C2 Exchange, Inc.

Cboe EDGA Exchange, Inc.

Cboe EDGX Exchange, Inc.

Cboe Exchange, Inc.

FINRA

Investors' Exchange LLC

Long-Term Stock Exchange, Inc.

MEMX LLC

MIAX PEARL, LLC

NYSE American LLC

NYSE Arca, Inc.

NYSE National, Inc.

NYSE Texas, Inc.

Nasdaq BX, Inc.

Nasdaq GEMX, LLC

Nasdaq ISE, LLC

Nasdaq MRX, LLC

Nasdaq PHLX LLC

Nasdaq Stock Market

New York Stock Exchange

Current Firm

SG AMERICAS SECURITIES, LLC

Contact information

FINRA licenses (52 States and Territories)

Documents

Direct owners and executive officers

Disclosures

Red Flags

Company Information

SG AMERICAS SECURITIES, LLC

TRUST BUT VERIFY

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