# EDGAR Filing Document

**Accession Number:** 0000789054
**File Stem:** 0000789054-26-000002
**Filing Date:** 2026-3
**Character Count:** 2511
**Document Hash:** a7a222389d0e064e23f388cbcf102b6b
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000789054-26-000002.hdr.sgml**: 20260330

**ACCESSION NUMBER**: 0000789054-26-000002

**CONFORMED SUBMISSION TYPE**: X-17A-5

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260330

**DATE AS OF CHANGE**: 20260330

**EFFECTIVENESS DATE**: 20260330

**PERIOD START**: 20250101

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MACK INVESTMENT SECURITIES, INC.
- **CENTRAL INDEX KEY:** 0000789054

**ORGANIZATION NAME:**
- **EIN:** 363423948
- **STATE OF INCORPORATION:** IL
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** X-17A-5
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 008-35536
- **FILM NUMBER:** 26813298

**BUSINESS ADDRESS:**
- **STREET 1:** 211 WAUKEGAN RD., SUITE 300
- **CITY:** NORTHFIELD
- **STATE:** IL
- **ZIP:** 60093
- **BUSINESS PHONE:** 847-657-6600

**MAIL ADDRESS:**
- **STREET 1:** 211 WAUKEGAN RD., SUITE 300
- **CITY:** NORTHFIELD
- **STATE:** IL
- **ZIP:** 60093

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MACK INVESTMENT SECURITIES INC                          /BD
- **DATE OF NAME CHANGE:** 19860205

### Attached PDF Documents

**Attachment 1:** `mackafspublic-1.pdf`

_No text found in this document._

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## FORM X-17A-5

### ANNUAL AUDITED REPORT

### Filer Information

**Filer CIK:** 0000789054

**Filer CCC:** XXXXXXXX

**Is this a LIVE or TEST filing?:** LIVE

**Would you like a Return Copy?:** No

### Submission Information

**Report Period Begin Date:** 01-01-2025

**Report Period End Date:** 12-31-2025

**Type of Registrant:** Broker-dealer

**Any material weaknesses identified?:** No

### Registrant Identification

**Name of Broker-Dealer:** MACK INVESTMENT SECURITIES, INC.

**Business Address:** 211 WAUKEGAN RD., SUITE 300, NORTHFIELD, IL, 60093

**Contact Person:** Stephen W Mack

**Contact Phone:** 8476576600

### Independent Public Accountant Identification

**Accountant Name:** Ohab and Company

**Accountant Address:** 100 East Sybelia Avenue, Suite 130, Maitland, FL, 32751

**Accountant Type:** Certified Public Accountant

### OATH OR AFFIRMATION

I, **Stephen W Mack**, swear (or affirm) that, to the best of my knowledge and belief, the accompanying financial statements and supporting schedules pertaining to the firm of **MACK INVESTMENT SECURITIES, INC.**, as of **12-31-2025**, are true and correct.

**Signature:** Stephen W Mack

**Title:** President