Fourthstone holds 9.96% of MainStreet Bancshares (MNSB) shares

Rhea-AI Filing Summary

Fourthstone LLC and related funds have disclosed a significant ownership position in MainStreet Bancshares, Inc. They report beneficial ownership of 767,792 shares of common stock, representing 9.96% of the company, based on 7,705,571 shares outstanding as of October 31, 2025.

Fourthstone holds the shares as an investment adviser on behalf of its advisory clients, including several affiliated funds, and L. Phillip Stone may be deemed to share beneficial ownership through his roles at these entities. The group states the shares were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of MainStreet Bancshares.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

MainStreet Bancshares, Inc.

(Name of Issuer)

Common Stock, par value $4.00 per share

(Title of Class of Securities)

56064Y100

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

Fourthstone LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 767,792.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 767,792.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

767,792.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

9.96 %

12

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

Fourthstone Master Opportunity Fund Ltd

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 603,757.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 603,757.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

603,757.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.84 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

Fourthstone GP LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 164,035.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 164,035.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

164,035.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.13 %

12

Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

Fourthstone QP Opportunity Fund LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 158,932.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 158,932.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

158,932.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

2.06 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

Fourthstone Small-Cap Financials Fund LP

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 5,103.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,103.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,103.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

0.07 %

12

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

CUSIP No. 56064Y100

1

Names of Reporting Persons

L. Phillip Stone, IV

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 767,792.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 767,792.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

767,792.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

9.96 %

12

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person: See Item 4 for a description of the information reported in rows (6), (8), (9) and (11).

SCHEDULE 13G

Item 1.
(a)	Name of issuer: MainStreet Bancshares, Inc.
(b)	Address of issuer's principal executive offices: 10089 FAIRFAX BOULEVARD, FAIRFAX, VA, 22030
Item 2.
(a)	Name of person filing: This Schedule 13G is being filed by Fourthstone LLC, a Delaware Limited Liability Company and Investment Adviser ("Fourthstone"). The persons reporting information on this Schedule 13G include, in addition to Fourthstone, a company incorporated in the Cayman Islands ("Fourthstone Master Opportunity Fund"), a Delaware Limited Partnership ("Fourthstone QP Opportunity"), a Delaware Limited Partnership ("Fourthstone Small-Cap Financials"), a Delaware Limited Liability Company ("Fourthstone GP, " General Partner of Fourthstone QP Opportunity and Fourthstone Small-Cap Financials), and L. Phillip Stone, IV, a citizen of the United States of America, who is the Managing Member of Fourthstone and Fourthstone GP (each, a "Reporting Person" and, together, the "Reporting Persons"). Fourthstone directly holds 767,792 shares of Common Stock on behalf of its advisory clients. Each of the Reporting Persons listed in this filing certify the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the Issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that effect.
(b)	Address or principal business office or, if none, residence: The principal business address of each of the Reporting Persons is as follows: The registered office of Fourthstone LLC, Fourthstone Master Opportunity Fund Ltd., Fourthstone GP LLC, Fourthstone QP Opportunity Fund LP, Fourthstone Small-Cap Financials Fund LP is 575 Maryville Centre Drive, Suite 110, St. Louis, MO 63141.
(c)	Citizenship: See response to Item 4 of each of the cover pages.
(d)	Title of class of securities: Common Stock, par value $4.00 per share
(e)	CUSIP No.: 56064Y100
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: Fourthstone LLC acquired the Issuer's shares in the ordinary course of business as a registered investment adviser and not with the purpose nor with the effect of influencing the control of the Issuer. Fourthstone GP LLC is the general partner of and may be deemed to beneficially own securities owned by Fourthstone QP Opportunity Fund LP and Fourthstone Small-Cap Financials Fund LP. L. Phillip Stone, IV, is the Managing Member of Fourthstone LLC and Fourthstone GP and may be deemed to beneficially own securities owned by Fourthstone. The percentages reported in Row 11 of each cover page are based on 7,705,571 shares of Common Stock (as defined below) of the Issuer (as defined below) outstanding as of October 31, 2025, based on the Issuer's Form 10-Q filed on November 7, 2025.
(b)	Percent of class: 9.96 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See responses to Item 5 on each cover page.
	(ii) Shared power to vote or to direct the vote: See responses to Item 6 on each cover page.
	(iii) Sole power to dispose or to direct the disposition of: See responses to Item 7 on each cover page.
	(iv) Shared power to dispose or to direct the disposition of: See responses to Item 8 on each cover page.
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Fourthstone LLC

Signature:	Amy M. Stone
Name/Title:	Chief Executive Officer
Date:	02/13/2026

Fourthstone Master Opportunity Fund Ltd

Signature:	Amy M. Stone
Name/Title:	Chief Executive Officer
Date:	02/13/2026

Fourthstone GP LLC

Signature:	L. Phillip Stone, IV
Name/Title:	Managing Member of Fourthstone GP LLC
Date:	02/13/2026

Fourthstone QP Opportunity Fund LP

Signature:	Amy M. Stone
Name/Title:	Chief Executive Officer
Date:	02/13/2026

Fourthstone Small-Cap Financials Fund LP

Signature:	Amy M. Stone
Name/Title:	Chief Executive Officer
Date:	02/13/2026

L. Phillip Stone, IV

Signature:	L. Phillip Stone, IV
Name/Title:	Self, Principal owner of Fourthstone LLC
Date:	02/13/2026

FAQ

What stake does Fourthstone hold in MainStreet Bancshares (MNSB)?

Fourthstone and related entities report beneficial ownership of 767,792 shares of MainStreet Bancshares common stock, equal to 9.96% of the outstanding shares, based on 7,705,571 shares outstanding as of October 31, 2025.

Who are the reporting persons in the MainStreet Bancshares (MNSB) Schedule 13G/A?

The reporting persons are Fourthstone LLC, Fourthstone Master Opportunity Fund Ltd, Fourthstone GP LLC, Fourthstone QP Opportunity Fund LP, Fourthstone Small-Cap Financials Fund LP, and L. Phillip Stone IV, who is managing member of Fourthstone and Fourthstone GP.

Is Fourthstone seeking to influence control of MainStreet Bancshares (MNSB)?

The reporting group states the MainStreet Bancshares shares were acquired and are held in the ordinary course of business and not for the purpose or effect of changing or influencing control of the issuer or participating in any control-related transaction.

How many MainStreet Bancshares (MNSB) shares does Fourthstone Master Opportunity Fund hold?

Fourthstone Master Opportunity Fund Ltd reports 603,757 shares of MainStreet Bancshares common stock, with shared voting and dispositive power over that amount, representing 7.84% of the company’s outstanding common stock as referenced in the ownership disclosure.

What is L. Phillip Stone’s reported ownership in MainStreet Bancshares (MNSB)?

L. Phillip Stone IV is reported to beneficially own 767,792 shares of MainStreet Bancshares, or 9.96% of the common stock, through his position as managing member of Fourthstone LLC and Fourthstone GP, which manage and advise the holding entities.

On what date was the ownership event triggering this MainStreet Bancshares (MNSB) report?

The date of the event requiring this ownership statement is listed as December 31, 2025. The percentage calculations use 7,705,571 shares outstanding as of October 31, 2025, based on MainStreet Bancshares’ Form 10-Q filed November 7, 2025.