IGMS IGM Biosciences Inc

FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES                                                                                   
OMB APPROVAL
OMB Number: 3235-0287
Estimated average burden
hours per response... 0.5                       
Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940                       

1. Name and Address of Reporting Person * Chen Daniel ShinYu	2. Issuer Name and Ticker or Trading Symbol IGM Biosciences, Inc. [ IGMS ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director                    _____ 10% Owner __X__ Officer (give title below)    _____ Other (specify below) Chief Medical Officer
(Last)          (First)          (Middle) C/O IGM BIOSCIENCES, INC., 325 E. MIDDLEFIELD ROAD	3. Date of Earliest Transaction (MM/DD/YYYY) 9/17/2020
(Street) MOUNTAIN VIEW, CA 94043 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security (Instr. 3)	2. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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	9/17/2020		M(1)		950	A	$1.39	117468	D
Common Stock	9/17/2020		F		341 (2)	D	$71.14	117127	D
Common Stock	9/18/2020		S(1)		609	D	$77.91	116518	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		7. Title and Amount of Securities Underlying Derivative Security (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
Stock Option (right to buy)	$1.39	9/17/2020		M (1)			950	(3)	12/30/2028	Common Stock	950	$0.00	358240	D

Explanation of Responses:
(1)	The option exercise and sale reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan entered into by the Reporting Person.
(2)	Represents shares withheld by the Issuer to pay the exercise price and taxes pursuant to the "net exercise" of 950 option shares.
(3)	The option, originally for 361,090 shares, of which 2,850 shares have been exercised, vested as to 1/4 of the shares on August 1, 2019, and an additional 1/48 of the shares subject to the option shall vest monthly thereafter, subject to the Reporting Person remaining a service provider through each such date.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Chen Daniel ShinYu C/O IGM BIOSCIENCES, INC. 325 E. MIDDLEFIELD ROAD MOUNTAIN VIEW, CA 94043			Chief Medical Officer

Signatures
/s/ Misbah Tahir, by power of attorney		9/18/2020
**Signature of Reporting Person		Date