[SCHEDULE 13G/A] Nuveen Mortgage & Income Fund/MA/ SEC Filing

Rhea-AI Filing Summary

Sit Investment Associates, Inc. and its subsidiary Sit Fixed Income Advisors II, LLC reported shared voting and dispositive power over 1,228,685 shares of Nuveen Mortgage and Income Fund common stock, representing 22.4% of the class. The percentage is calculated using 5,476,626 shares outstanding as of June 30, 2025, per the issuer's Form N-CSRS. All securities are owned by client accounts managed by SIA and SFI; both firms state they exercise those powers in their roles as registered investment advisers and disclaim beneficial ownership under Rule 13d-4. The filing is signed by Paul E. Rasmussen, Vice President, on October 2, 2025, and includes a Joint Filing Agreement as Exhibit A.

Positive

• 1,228,685 shares reported, representing a material 22.4% of the class

Negative

• None.

Insights

Institutional Investor Analyst

TL;DR: Sit reports shared control of 1,228,685 shares, equal to 22.4% of JLS outstanding stock.

SIA and SFI disclose they possess shared voting and shared dispositive power over the reported position, which is held in client accounts and totals 1,228,685 shares based on 5,476,626 outstanding shares as of June 30, 2025.

The firms expressly disclaim beneficial ownership under Rule 13d-4, indicating the position reflects advisory control rather than proprietary ownership; this distinction matters for governance and disclosure but is a factual statement contained in the filing.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 7)

Nuveen Mortgage and Income Fund

(Name of Issuer)

Common Stock

(Title of Class of Securities)

670735109

(CUSIP Number)

09/30/2025

(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. 670735109

1

Names of Reporting Persons

Sit Investment Associates, Inc.

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

MINNESOTA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,228,685.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,228,685.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,228,685.00

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)

22.4 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

CUSIP No. 670735109

1

Names of Reporting Persons

Sit Fixed Income Advisors II, 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 1,228,685.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,228,685.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,228,685.00

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)

22.4 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Nuveen Mortgage and Income Fund
(b)	Address of issuer's principal executive offices: 333 West Wacker Drive, Chicago, Illinois 60606
Item 2.
(a)	Name of person filing: Sit Investment Associates, Inc. Sit Fixed Income Advisors II, LLC
(b)	Address or principal business office or, if none, residence: c/o Sit Investment Associates, Inc. 80 South Eighth Street, Suite 3300 Minneapolis, MN 55402
(c)	Citizenship: Sit Investment Associates, Inc. Minnesota Corporation Sit Fixed Income Advisors II, LLC Delaware LLC
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 670735109
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: See response to item 9 on each cover page.
(b)	Percent of class: See response to item 11 on each cover page.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See response to item 5 on each cover page.
	(ii) Shared power to vote or to direct the vote: See response to item 6 on each cover page.
	(iii) Sole power to dispose or to direct the disposition of: See response to item 7 on each cover page.
	(iv) Shared power to dispose or to direct the disposition of: See response to item 8 on each cover page. The ownership percentages reported are based on 5,476,626 shares of common stock outstanding as of June 30, 2025, as reported in the Issuer's Report on Form N-CSRS filed with the Securities Exchange Commission. Sit Investment Associates, Inc. ("SIA") is an investment adviser registered under section 203 of the Investment Advisers Act of 1940. Sit Fixed Income Advisors II, LLC ("SFI") is an investment adviser registered under section 203 of the Investment Advisers Act of 1940 and a subsidiary of SIA. SIA and SFI provide investment management services to client accounts ("Accounts"). In their roles as investment advisers SIA and SFI possess shared voting and investment power over securities of the Issuer described in this schedule 13G owned by the Accounts and may be deemed to be the beneficial owner of such shares of the Issuer owned by the Accounts. All securities reported in this schedule 13G are owned by the Accounts. Pursuant to Rule 13d-4 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), SIA and SFI disclaim beneficial ownership of such securities.
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. The Accounts are known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities. Except as may be indicated if this is a joint filing with a registered investment company managed by SIA or SFI, not more than 5% of the class of such securities is owned by any one Account subject to the investment advice of SIA or SFI.
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.

Sit Investment Associates, Inc.

Signature:	/s/ Paul E. Rasmussen
Name/Title:	Paul Rasmussen / Vice President
Date:	10/02/2025

Sit Fixed Income Advisors II, LLC

Signature:	/s/ Paul E. Rasmussen
Name/Title:	Paul Rasmussen / Vice President
Date:	10/02/2025

Exhibit Information

Exhibit A - Joint Filing Agreement

FAQ

What stake do Sit Investment Associates and Sit Fixed Income Advisors II hold in JLS?

They report shared voting and dispositive power over 1,228,685 shares, equal to 22.4% of the common stock.

How was the 22.4% ownership percentage calculated?

The percentage uses 5,476,626 shares outstanding as reported on the issuer's Form N-CSRS as of June 30, 2025.

Do Sit advisors claim beneficial ownership of the shares?

No. SIA and SFI state the shares are owned by client accounts and they disclaim beneficial ownership under Rule 13d-4.

Who signed the Schedule 13G/A and when?

The filing is signed by Paul E. Rasmussen, Vice President, for both filers on October 2, 2025.

Where are SIA and SFI organized?

Sit Investment Associates, Inc. is organized in Minnesota and Sit Fixed Income Advisors II, LLC is organized in Delaware.