Firm profile

Gagnon Securities, LLC

NEW YORK, NYCRD 103727Registration Status: ApprovedEffective since October 21, 2005SEC # 801-64836Latest ADV August 12, 2026

Gagnon Securities, LLC is an SEC registered investment adviser organized as a limited liability company with a primary office location in New York, NY. Its latest Form ADV filing, dated August 12, 2026, reports $530M in regulatory assets under management, 19 employees, 1 office, and 1,202 accounts.

Assets Under Management
$530M
Employees
19
Offices
1 office
Total Clients
1,202

Associated firm names

1 name listed
  • GAGNON SECURITIES, LLC

Leadership

3 roles identified
CEONeil Joseph Gagnon
CCOLisa Catherine Ferrante
CFOMarianne D'alessandro

Advisory services offered

1 types reported
Portfolio management for individuals and small businesses

Fee models offered

2 types reported
Asset based fees
Commissions

Offices & Contact

Primary office

NEW YORK, New York, United States

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Primary office regionOther reported regions

Shading shows states and countries with reported offices. Cities are listed below; shading does not indicate service coverage.

New York

NEW YORKPrimary office

1 office records listed · 1 total offices reported. Counts can use different reporting dates. SEC filers may list only their largest 25 additional offices.

Contact and digital presence

ADV profile links

Regulatory Assets Under Management Breakdown

Total regulatory assets under management$530Mas of August 12, 2026
Discretionary100.0%
$530M
100% of total RAUM100.0%
Non-discretionary0.0%
$0
0% of total RAUM0.0%
All regulatory assets under management are discretionary.

Client Coverage Demographics

Top client segmentIndividuals represent 85.3% of total clients.
Top client categories% of clientsClients
1
Individuals
85.3%
1,025
2
Corporations
12.0%
144
3
HNWI
2.7%
33

Assets under management Growth by Quarter

Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.

Total AUM$530M
Total Accounts1,202
10Y AUM Change+$343M (+184.4%)

Private Funds

Private funds reported by Gagnon Securities, LLC

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Employee Growth by Quarter

Quarterly points use the latest ADV filing or SEC roster snapshot available in each quarter.

Total Employees19
Clients per Employee63:1
10Y Employee Change-7 (-26.9%)

Historical AUM and employee figures reflect available SEC Form ADV filings under this CRD. Filing gaps may reflect registration status changes, dormant periods, state registration periods, firm restructuring, or other reporting changes. Rialytix does not interpolate missing periods.


Ownership

Reported direct and indirect ownership ranges

Each range applies to a separate reported relationship and should not be added together.

Reported ownership ranges

Highlighted bands show the percentage range reported in Form ADV.

0%25%50%75%100%
NEIL JOSEPH GAGNONDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
25% to < 50%
BRIAN JOSEPH GAGNONDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
10% to < 25%
MAUREEN ONEILL DREWDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
10% to < 25%
WILLIS GITT TAYLORDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
10% to < 25%
MATTHEW HOWARD JAMPOLEDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
HENRY CARL BEINSTEINDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
JONATHAN WILLIAMS ROBOHMDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
DWIGHT EISENHOWER LEEDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
LISA CATHERINE FERRANTEDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
ALISON O'BRIEN TRANCHIDADirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
MARIANNE D'ALESSANDRODirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
ADRIENNE MICHELLE GAROFALODirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
SARAH G JILLADirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
CYNTHIA ANDREA ROBERTSDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
JAMES MATTHEW CAPPELLODirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
JESSICA ROSE VINGIELLODirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
JAMES COLBYDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%
GABRIELLE ROSENFELDDirect owner · Schedule AInterest in GAGNON SECURITIES, LLC
< 5%

Bars represent the reported range at that individual ownership step, not an estimated percentage of the advisory firm. Indirect relationships may refer to intermediate entities rather than directly to Gagnon Securities, LLC.

No indirect ownership information reported in the source’s Schedule B.

Reported ownership and control details

Form ADV · Filing date 2026-08-12 · Schedules A and B

23 entries
#Owner / person & roleInterest in entityReported interestControl personTitle / status acquiredSource
1NEIL JOSEPH GAGNONMANAGER/CEOIndividualGAGNON SECURITIES, LLC25% to less than 50%Code CYesMANAGER/CEO10/1999Schedule APDF page 27
2BRIAN JOSEPH GAGNONMEMBERIndividualGAGNON SECURITIES, LLC10% to less than 25%Code BYesMEMBER01/2002Schedule APDF page 27
3MAUREEN ONEILL DREWMEMBERIndividualGAGNON SECURITIES, LLC10% to less than 25%Code BYesMEMBER01/2002Schedule APDF page 27
4MATTHEW HOWARD JAMPOLEMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER12/2004Schedule APDF page 27
5HENRY CARL BEINSTEINMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER04/2005Schedule APDF page 27
6JONATHAN WILLIAMS ROBOHMMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER04/2005Schedule APDF page 27
7DWIGHT EISENHOWER LEEMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER08/2005Schedule APDF page 27
8LISA CATHERINE FERRANTEMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesMEMBER02/2006Schedule APDF page 27
9ALISON O'BRIEN TRANCHIDAMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesMEMBER03/2007Schedule APDF page 27
10WILLIS GITT TAYLORMEMBERIndividualGAGNON SECURITIES, LLC10% to less than 25%Code BYesMEMBER05/2008Schedule APDF page 27
11MARIANNE D'ALESSANDROMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesMEMBER03/2011Schedule APDF page 27
12ADRIENNE MICHELLE GAROFALOMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER03/2015Schedule APDF page 27
13MARIANNE D'ALESSANDROCHIEF FINANCIAL OFFICERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesCHIEF FINANCIAL OFFICER08/2017Schedule APDF page 27
14ALISON ANNE TRANCHIDAOPERATIONS MANAGERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesOPERATIONS MANAGER12/2017Schedule APDF page 27
15LISA CATHERINE FERRANTECHIEF COMPLIANCE OFFICERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesCHIEF COMPLIANCE OFFICER12/2017Schedule APDF page 27
16LISA CATHERINE FERRANTECROP/ROPIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesCROP/ROP12/2017Schedule APDF page 27
17SARAH G JILLAMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2018Schedule APDF page 27
18CYNTHIA ANDREA ROBERTSMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2018Schedule APDF page 27
19JAMES MATTHEW CAPPELLOMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2021Schedule APDF page 27
20LISA CATHERINE FERRANTECHIEF ADMINISTRATIVE OFFICERIndividualGAGNON SECURITIES, LLCLess than 5%Code NAYesCHIEF ADMINISTRATIVE OFFICER02/2023Schedule APDF page 27
21JESSICA ROSE VINGIELLOMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2025Schedule APDF page 27
22JAMES COLBYMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2024Schedule APDF page 27
23GABRIELLE ROSENFELDMEMBERIndividualGAGNON SECURITIES, LLCLess than 5%Code NANoMEMBER01/2024Schedule APDF page 27

Less than 5% may include zero. Code F identifies a role without specifying a percentage. Reported interests may overlap and may not include every owner. Total indirect ownership is not calculated.

Compliance & Disclosures

Responses were selected by the RIA in its filing. Questions are shortened for readability; “you” refers to the reporting firm, and some questions also cover advisory affiliates.

Item 11 responses have not been pulled yet for this RIA.

RIA or supervised-person involvementThe RIA’s response about whether these events involve the firm or its supervised persons is unavailable.RIA responseUnavailable
AFelonies2 Unavailable

In the past ten years, have you or any advisory affiliate:

  • A1Been convicted of or pleaded guilty or no contest to a felony?Unavailable
  • A2Been charged with a felony?Unavailable
BMisdemeanors2 Unavailable

In the past ten years, have you or any advisory affiliate:

  • B1Been convicted of or pleaded guilty or no contest to a misdemeanor involving investments, an investment-related business, fraud, false statements or omissions, wrongful taking of property, bribery, perjury, forgery, counterfeiting, or extortion?Unavailable
  • B2Been charged with a misdemeanor of the kind listed above?Unavailable
CSEC or CFTC actions5 Unavailable

Has the SEC or CFTC ever:

  • C1Found you or an advisory affiliate made a false statement or omission?Unavailable
  • C2Found you or an advisory affiliate violated SEC or CFTC regulations or statutes?Unavailable
  • C3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?Unavailable
  • C4Entered an order against you or an advisory affiliate in connection with investment-related activity?Unavailable
  • C5Imposed a civil money penalty on you or an advisory affiliate, or ordered you or an advisory affiliate to cease and desist from any activity?Unavailable
DOther regulatory actions5 Unavailable

Has any other federal regulatory agency, state regulatory agency, or foreign financial regulatory authority ever:

  • D1Found you or an advisory affiliate made a false statement or omission, or was dishonest, unfair, or unethical?Unavailable
  • D2Found you or an advisory affiliate violated investment-related regulations or statutes?Unavailable
  • D3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?Unavailable
  • D4In the past ten years, entered an order against you or an advisory affiliate in connection with investment-related activity?Unavailable
  • D5Denied, suspended, or revoked your or an advisory affiliate’s registration or license, or otherwise prevented association with an investment-related business or restricted activities?Unavailable
ESelf-regulatory organization actions4 Unavailable

Has a self-regulatory organization or commodities exchange ever:

  • E1Found you or an advisory affiliate made a false statement or omission?Unavailable
  • E2Found you or an advisory affiliate violated its rules, other than a violation designated as a minor rule violation under an SEC-approved plan?Unavailable
  • E3Found you or an advisory affiliate caused an investment-related business to have its authorization to do business denied, suspended, revoked, or restricted?Unavailable
  • E4Disciplined you or an advisory affiliate by expulsion, suspension, barring association with other members, or otherwise restricting activities?Unavailable
FProfessional authorizations1 Unavailable
  • FHas an authorization to act as an attorney, accountant, or federal contractor granted to you or an advisory affiliate ever been revoked or suspended?Unavailable
GPending regulatory proceedings1 Unavailable
  • GAre you or any advisory affiliate now the subject of a regulatory proceeding that could result in a “Yes” answer to any part of C, D, or E?Unavailable
HCivil judicial actions and proceedings4 Unavailable

(1) Court actions

Has a domestic or foreign court:

  • H(1)(a)In the past ten years, enjoined you or an advisory affiliate in connection with investment-related activity?Unavailable
  • H(1)(b)Found that you or an advisory affiliate violated investment-related statutes or regulations?Unavailable
  • H(1)(c)Dismissed, pursuant to a settlement agreement, an investment-related civil action brought against you or an advisory affiliate by a state or foreign financial regulatory authority?Unavailable

(2) Pending civil proceedings

  • H(2)Are you or any advisory affiliate now the subject of a civil proceeding that could result in a “Yes” answer to any part of H(1)?Unavailable

* Metrics are based on the latest available data, including Form ADV filings, brochures, and relationship summaries pulled from the SEC IAPD, and may be subject to change. Learn what is included in the Rialytix data. Please refer to the firm's official disclosures for the most accurate information using their CRD number. This is not investment advice.