AdvisorCheck - Find and Connect with Top Financial Advisors on Your Terms
Advisor Search
Why AdvisorCheck

We're Here To Help

AdvisorCheck empowers you to find, evaluate, and monitor financial advisors with confidence and clarity.

Advisor Monitoring

Financial advisor's situations can change, sometimes without notice. AdvisorCheck's Monitoring tool helps you avoid surprises and stay on top of your financial health.

Firm Stability Insights

The stability of your financial advisor's firm has a significant impact in the security and quality of service you receive. Our tool provides historical data and key insights over time to help you make informed, confident decisions.

Pricing
For Advisors
BS

Brandon W. Sullivan

CALAMOS FINANCIAL SERVICES LLC
NAPERVILLE, IL 60563-2787
Some features on this profile are disabled
CRD#: 6958873
BS

Professional summary

Brandon William Sullivan is a registered financial professional currently at CALAMOS FINANCIAL SERVICES LLC located in Naperville, Illinois.

Brandon is registered as a RR (Registered Representative) and started their career in finance in 2025. Brandon has worked at 1 firm and has passed the Series 99TO and SIE exams.

Question & Answer

Are you a "fiduciary"?
No

Aliases

None

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 Brandon William Sullivan'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

August 27, 2025 - Present

CALAMOS FINANCIAL SERVICES LLC

Office #1: 2020 Calamos Court, Naperville, IL 60563-2787
BD
CRD#: 19850
NAPERVILLE, IL

State Registrations and Notice Filings

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

Visual representation of state registrations

This advisor is not registered in any state.

Exams

General Industry/Product Exam
RR
Series 99TO
Date: 8/26/2025
Operations Professional Examination
General Industry/Product Exam
RR
SIE
Date: 10/19/2022
Securities Industry Essentials Examination
SRO Registrations
RR
FINRA

Current Firm

CF
CALAMOS FINANCIAL SERVICES LLC
CALAMOS FINANCIAL SERVICES LLC | CALAMOS FINANCIAL SERVICES, INC.

CRD#: 19850 / SEC#: , 8-37854

BD
Broker-Dealer Firm Regulated by FINRA (Chicago district office)
Upgrade to AdvisorCheck Premium
Get A Biweekly Pulse, AutomaticallyReceive biweekly alerts automatically. Stay informed and proactive.
Catch Firm-Level Red Flags SoonerCatch leadership changes and disclosures early, before issues escalate.
See Trends. Not Just SnapshotsMonitor firm stability metrics like AUM and advisor ratios over time.

Contact information

Main Address
2020 Calamos Court, Naperville, IL 60563-2787
Mailing Address
2020 Calamos Court, Naperville, IL 60563-2787
Phone number
(630) 245-7200
Established
Delaware since 09/15/2004
Firm type
Limited Liability Company
Fiscal year end
December
Firm Size
Small
# of Employees

FINRA licenses (53 States and Territories)

Blank US states mapAlaskaHawaiiAlabamaArkansasArizonaCaliforniaColoradoConnecticutDelawareFloridaGeorgiaIowaIdahoIllinoisIndianaKansasKentuckyLouisianaMassachusettsMarylandMaineMichiganMinnesotaMissouriMississippiMontanaNorth CarolinaNorth DakotaNebraskaNew HampshireNew JerseyNew MexicoNevadaNew YorkOhioOklahomaOregonPennsylvaniaRhode IslandSouth CarolinaSouth DakotaTennesseeTexasUtahVirginiaVermontWisconsinWest VirginiaWyoming

Documents

Direct owners and executive officers

NamePositionCRD#
CALAMOS INVESTMENTS LLCSOLE MEMBER/MANAGER
KOUDOUNIS, JOHN SPIROPRESIDENT AND CHIEF EXECUTIVE OFFICER1878118
DUFRESNE, DANIEL LEOEVP, CHIEF OPERATING OFFICER2852606
HELMETAG, CHRISTIAN ALLANPRINCIPAL OPERATIONS OFFICER5282700
HELMETAG, CHRISTIAN ALLANFINANCIAL OPERATION PRINCIPAL5282700
KILEY, THOMAS PATRICKSVP CHIEF DISTRIBUTION OFFICER2869770
KILEY, THOMAS PATRICKPRINCIPAL EXECUTIVE OFFICER2869770
OJALA, ERIK DONALDGENERAL COUNSEL & SECRETARY4758365
SINKER, JACQUELINE ELIZABETHCHIEF COMPLIANCE OFFICER1471593

Disclosures

Regulatory Event1

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.

Company Information

CALAMOS FINANCIAL SERVICES LLC

CRD#: 19850Naperville, IL 60563-2787

TRUST BUT VERIFY

Monitor Brandon Sullivan

Get automatic monthly alerts on:
Job or Firm Moves
Licensing Changes
Client Complaints
New Red Flags
Contact Information Updates

Similar Advisors

JF
James FlanaganAdvisorCheck Check Mark
INDEPENDENT FINANCIAL GROUP, LLC
IAR
RR
Downers Grove, IL
FC
Flavia CardozoAdvisorCheck Check Mark
J.P. MORGAN SECURITIES LLC
IAR
RR
Naperville, IL
Justin John Dagostino
Justin DagostinoAdvisorCheck Check Mark
VERTEX PARTNERS
IAR
RR
Downers Grove, IL
footer-logo
How We Help
Advisor Search
Find Advisors by State
Blog
Glossary
For Advisors
About Us
Help Center
Terms Of UsePrivacy PolicySubscription Policy
Help Center
AdvisorCheck does not offer investment advice and should not replace discussions with professional accounting, tax, legal or financial advisors.© 2026 AdvisorCheck, an AIMR Analytics company. All rights reserved.