Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Smith Nicholas Conrad 2. Issuer Name and Ticker or Trading Symbol Alto Neuroscience, Inc. [ANRO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) PRESIDENT AND CFO (Last) (First) (Middle) C/O ALTO NEUROSCIENCE, INC., 650 CASTRO STREET, SUITE 450 3. Date of Earliest Transaction (Month/Day/Year) 09/29/2026 (Street) MOUNTAIN VIEW, CA 94041 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 09/29/2026 M(1) 56,455 A $2.35 80,515 D Common Stock 09/29/2026 M(1) 54,375 A $2.35 134,890 D Common Stock 09/29/2026 S(1) 110,830 D $26.5826(2) 24,060 D Common Stock 09/30/2026 M(1) 24,056 A $2.35 48,116 D Common Stock 09/30/2026 S(1) 23,170 D $25.7786 24,946 D Common Stock 09/30/2026 S(1) 886 D $26.87 24,060 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Employee Stock Option (Right to Buy)

$2.35

09/29/2026

M(1)

56,455

(3)

12/19/2033

Common Stock

56,455

$ 0

145,874

D

Employee Stock Option (Right to Buy)

$2.35

09/29/2026

M(1)

54,375

(4)

02/28/2034

Common Stock

54,375

$ 0

35,625

D

Employee Stock Option (Right to Buy)

$2.35

09/30/2026

M(1)

24,056

(3)

12/19/2033

Common Stock

24,056

$ 0

121,818

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Smith Nicholas Conrad C/O ALTO NEUROSCIENCE, INC. 650 CASTRO STREET, SUITE 450 MOUNTAIN VIEW, CA 94041			PRESIDENT AND CFO

Signatures

/s/ Erin R. McQuade, Attorney-in-Fact		10/01/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	This transaction was pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 30, 2026.
(2)	This price is a weighted average price. These securities were sold in multiple transactions at prices ranging from $26.5513 to $26.5902 inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of securities sold at each separate price within the range set forth in this footnote.
(3)	One-third (1/3rd) of the shares underlying the option vested upon the completion of the Issuer's initial public offering and two-thirds (2/3) of the shares underlying the option vested or shall vest over a period of four years. 25% of the shares underlying the time-based portion vested on December 20, 2024, and 1/48 of the shares underlying the time-based portion vested or shall vest on a monthly basis thereafter, subject to the Reporting Person's continuous service through such vesting date.
(4)	25% of the shares underlying the option vested on March 1, 2025, and one forty-eighth (1/48th) of the shares underlying the option vested or shall vest in monthly installments thereafter, subject to the Reporting Person's continuous service through each such vesting date.

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