MACK INVESTMENT SECURITIES, INC.

CRD 17643File 801-29570

APPROVED

Retail clients

Filing as of Mar 31, 2026

Feed vintage Aug 17, 2026

Regulatory AUM

$302.6M

Below cohort median (national)

Discretionary AUM

$214.6M

Non-discretionary $87.9M

Clients

673

1,017 accounts

Employees

Below cohort median in IL

Identity & registration

ADV Item 1

Organization form: Corporation
Firm type: Registered
SEC region: CHRO
Registration date: May 28, 1987
Principal office: 211 WAUKEGAN ROAD, STE 300, NORTHFIELD, IL, 60093
Phone: 847-657-6600
Website: HTTP://WWW.MACKTRACKS.COM

Assets & accounts

ADV Item 5F

Total regulatory AUM: $302.6M
Discretionary AUM: $214.6M
Non-discretionary AUM: $87.9M
Discretionary accounts: 729
Non-discretionary accounts: 288
Total accounts: 1,017
AUM per client: $450K

Clients by type

ADV Item 5D

Client type	Clients	AUM
High net worth individuals	282	$230.8M
Pension and profit sharing plans	12	$6.8M
Individuals (other than high net worth individuals)	379	$65.0M

Compensation & activities

ADV Items 5E, 5G

Compensation

Fixed fees
Commissions
Hourly charges
A percentage of assets under your management

Advisory activities

Publications
Educational seminars
Financial planning services
Selection of other advisers
Portfolio management for individuals and/or small businesses

Custody

ADV Item 9

Firm Custody Cash: No
Firm Custody Assets: No
Firm Custody Clients: No
Firm Custody Securities: No
Related Person Custody Cash: No
Related Person Custody Assets: No
Related Person Custody Clients: No
Related Person Custody Securities: No

Disclosure events

ADV Item 11

This firm answered no to every Item 11 disclosure question in this filing.

Filed changes

Date	Field	From	To
Aug 12, 2026	Registration	—	APPROVED

Every value above is reproduced from this firm's Form ADV filing. Fields the firm left blank are shown as “Not reported” rather than filled in from other sources.