SourcingSourcing

MACK INVESTMENT SECURITIES, INC.

B53
CRD 17643·SEC 801-29570·NORTHFIELD, IL
AUM
$302.6M
$100M-$500M
Est. Revenue
$3.0M
@ 1% on AUM
Est. EBITDA
$908K
@ 30% margin
Est. Deal Value
$7.3M
@ 8× EBITDA

Identity

Registrations & legal identity

Legal name
MACK INVESTMENT SECURITIES, INC.
CRD
17643
SEC file #
801-29570
EIN
—
DBA names
—

Economics

AUM
$302.6M
AUM band
$100M-$500M
AUM trajectory
'20'26
$163.5M → $302.6M▲ +85%
Client mix
Individuals Other379
Individuals High Net Worth282
Pension Profit Sharing Plans12

Operations

Employees (total)
8
Advisory staff (per ADV)
8
Advisory staff (5-yr trend)
'20'26
2 advisors → 8 advisors▲ +300%
Primary office
NORTHFIELD IL
Branches
—

Custodian & Brokerage

Primary custodian
E*Tradelow confidence
Services offered
Financial planningPortfolio mgmt — individualsSelection of other advisersPublication of periodicals
Fee basis
% of AUMHourly chargesFixed feesCommissions

Filings

Latest ADV filing
03/31/2026
ADV-W filed at
—
Website
macktracks.com

Compliance

Disclosures (firm)
0
Trademark
—
Additional signalsExpand ▾

Ownership & succession ★

Who controls the firm + pre-computed succession flags

Top Owner Name
MACK, STEPHEN WALTER
Top Owner Pct
87.5
Top Owner Entity Kind
I
Owner Count
1
Control Persons
MACK, STEPHEN WALTER
Solo Advisor Indicator
No
Succession Risk Solo Owner
Yes
Is Parent Owned Subsidiary
No

Availability / M&A ★

Already-acquired = skip; deal comps

Adv W Filed
No

Web presence ★

Stale website = winding down

Web Signal Quality
ok
Rdap Domain
MACKTRACKS.COM
Rdap Domain Creation Date
1996-11-17T05:00:00Z
Rdap Firm Age Years
30
Rdap Firm Age Band
20+y
Rdap Registrar
GoDaddy.com, LLC

Retirement-plan book (Form 5500) ★

401(k)/plan business — cross-sell value

Retirement Plan Book
No

SEC EDGAR

Edgar Registered
No

Compliance & brand

Firm Registration Status
active

All other collected signals (14)

Everything else we've pulled for this record, not yet curated into a section.

Adv W Recently Filed
No
Bc Firm Active Bc Count
12
Bc Firm Active IA Count
8
Bc Firm IAR Count
12
Custodian Candidates
Full
E*trade4
Axos Advisor Services2
Firm Has Custody
No
Mailing Office Differs
No
Rdap Domain Expiration Date
2026-11-16T05:00:00Z
Rdap Domain Last Changed
2025-11-17T11:30:26Z
Rdap Nameservers
Ns53.domaincontrol.comNs54.domaincontrol.com
Rdap Secure Dns Enabled
No
Rdap Status
Client Delete ProhibitedClient Renew ProhibitedClient Transfer ProhibitedClient Update Prohibited
Top Owner CRD
1007322
Trust Company Affiliate
No

People (12)

12
MACK, STEPHEN WALTER
IAR · Direct Owner · 87.5%
1007322
JOAN BARBARA HAVENS
IAR
4479596
STEVEN BRIAN MILSTEIN
IAR
2204646
LISA PRESTIA
IAR
4446711
SHELDON DAVID KAIZ
IAR
1281232
JOHN RUSSELL BUDZIAK
IAR
1770016
NORMAN PETER CHIODRAS
IAR
1304974
JOHN ANTHONY KELTY
IAR
1735615
MICHAEL STEPHEN MACK
IAR
4814988
KEVIN EDWARD MACK
IAR
5167264
JOHN JOSEPH COMISKEY
IAR
5531452
CYNTHIA MADELYN JENKINS
IAR
706510