# EDGAR Filing Document

**Accession Number:** 0001487428
**File Stem:** 0001140361-26-008128
**Filing Date:** 2026-3
**Character Count:** 3398
**Document Hash:** f585d0c812885c985d9b698fc686b84d
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001140361-26-008128.hdr.sgml**: 20260306

**ACCESSION NUMBER**: 0001140361-26-008128

**CONFORMED SUBMISSION TYPE**: 424B3

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260306

**DATE AS OF CHANGE**: 20260305

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Horizon Technology Finance Corp
- **CENTRAL INDEX KEY:** 0001487428

**ORGANIZATION NAME:**
- **EIN:** 272114934
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 424B3
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-290114
- **FILM NUMBER:** 26728311

**BUSINESS ADDRESS:**
- **STREET 1:** 312 FARMINGTON AVENUE
- **CITY:** FARMINGTON
- **STATE:** CT
- **ZIP:** 06032
- **BUSINESS PHONE:** 860-676-8654

**MAIL ADDRESS:**
- **STREET 1:** 312 FARMINGTON AVENUE
- **CITY:** FARMINGTON
- **STATE:** CT
- **ZIP:** 06032

------

#### Filed Pursuant to Rule 424(b)(3)

#### Registration No. No. 333-290114

#### HORIZON TECHNOLOGY FINANCE CORPORATION

#### MONROE CAPITAL CORPORATION

#### Supplement No. 1, dated March 5, 2026, to the

#### Joint Proxy Statement/Prospectus, dated January 16, 2026

This supplement contains information that amends, supplements or modifies certain information contained in the combined prospectus of Horizon Technology Finance Corporation ("HRZN"), and definitive joint proxy statement of HRZN and Monroe Capital Corporation ("MRCC"), dated January 16, 2026 (the "Joint Proxy Statement/Prospectus"). This supplement is part of, and should be read in conjunction with, the Joint Proxy Statement/Prospectus. The Joint Proxy Statement/Prospectus has been filed with the U.S. Securities and Exchange Commission (the "SEC"), and is available free of charge at www.sec.gov or by calling HRZN at (860) 676-8654, or by writing to HRZN at 312 Farmington Avenue, Farmington, Connecticut 06032, Attention: Investor Relations, or by calling MRCC at (312) 258-8300, or by writing to MRCC at 155 North Wacker Drive, 35th Floor, Chicago, Illinois 60606, Attention: Investor Relations. Capitalized terms used herein but not defined shall have the meanings ascribed to such terms in the Joint Proxy Statement/Prospectus.

#### INCORPORATION BY REFERENCE FOR HRZN

This supplement incorporates by reference the documents set forth below that have previously been filed with the SEC:

<br> • HRZN's Annual Report on Form 10-K for the period ended December 31, 2025, filed with the SEC on [March 3, 2026](https://www.sec.gov/Archives/edgar/data/1487428/000143774926006636/hrzn20251231_10k.htm); and

<br> • HRZN's Current Report on Form 8-K (other than information furnished rather than filed) filed with the SEC on [February 11, 2026](https://www.sec.gov/Archives/edgar/data/1487428/000143774926003812/hrzn20260210_8k.htm).

#### INCORPORATION BY REFERENCE FOR MRCC

This supplement incorporates by reference the documents set forth below that have previously been filed with the SEC:

<br> • MRCC's Annual Report on Form 10-K for the period ended December 31, 2025, filed with the SEC on [March 5, 2026](https://www.sec.gov/Archives/edgar/data/1512931/000151293126000011/mrcc-20251231.htm); and

<br> • MRCC's Current Report on Form 8-K (other than information furnished rather than filed) filed with the SEC on [January 15, 2026](https://www.sec.gov/Archives/edgar/data/1512931/000110465926004084/tm263281d1_8k.htm).

------