SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Skyline Venture Partners V LP (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1350 (Street) PALO ALTO CA 94301 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol SI-BONE, Inc. [ SIBN ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 10/19/2018
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X 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. 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	10/19/2018		C		2,213,425	A	(1)	2,213,425	I	By Skyline Venture Partners V, L.P.(2)
Common Stock	10/19/2018		C		792,195	A	(1)	3,005,620	I	By Skyline Venture Partners V, L.P.(2)
Common Stock	10/19/2018		C		690,689	A	(3)	3,696,309	I	By Skyline Venture Partners V, L.P.(2)
Common Stock	10/19/2018		C		398,676	A	(1)	4,094,985	I	By Skyline Venture Partners V, L.P.(2)
Common Stock	10/19/2018		P		325,000	A	$15	4,419,985	I	By Skyline Venture Partners V, L.P.(2)

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 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: 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
Warrant (right to buy)	$9.1	10/19/2018		X			39,421	(4)	(4)	Series 5 Preferred Stock	39,421	$0.00	0	I	By Skyline Venture Partners V, L.P.(2)
Series 5 Preferred Stock	$9.1	10/19/2018		X		39,421		(1)	(1)	Common Stock	39,421	$0.00	816,099	I	By Skyline Venture Partners V, L.P.(2)
Series 5 Preferred Stock	(1)	10/19/2018		S(5)			23,904	(1)	(1)	Common Stock	23,904	$14	792,195	I	By Skyline Venture Partners V, L.P.(2)
Series 4 Preferred Stock	(1)	10/19/2018		C			2,213,425	(1)	(1)	Common Stock	2,213,425	(1)	0	I	By Skyline Venture Partners V, L.P.(2)
Series 5 Preferred Stock	(1)	10/19/2018		C			792,195	(1)	(1)	Common Stock	792,195	(1)	0	I	By Skyline Venture Partners V, L.P.(2)
Series 6 Preferred Stock	(3)	10/19/2018		C			652,347	(3)	(3)	Common Stock	690,689	(3)	0	I	By Skyline Venture Partners V, L.P.(2)
Series 7 Preferred Stock	(1)	10/19/2018		C			398,676	(1)	(1)	Common Stock	398,676	(1)	0	I	By Skyline Venture Partners V, L.P.(2)

1. Name and Address of Reporting Person* Skyline Venture Partners V LP (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1350 (Street) PALO ALTO CA 94301 (City) (State) (Zip)

1. Name and Address of Reporting Person* Skyline Venture Management V, LLC (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1350 (Street) PALO ALTO CA 94301 (City) (State) (Zip)

1. Name and Address of Reporting Person* Freund John Gordon (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1350 (Street) PALO ALTO CA 94301 (City) (State) (Zip)

1. Name and Address of Reporting Person* KANEKO YASUNORI (Last) (First) (Middle) 525 UNIVERSITY AVENUE, SUITE 1350 (Street) PALO ALTO CA 94301 (City) (State) (Zip)

Explanation of Responses:

1. The Issuer's Series 4 Preferred Stock, Series 5 Preferred Stock and Series 7 Preferred Stock automatically converted into an equal number of shares of Issuer's common stock immediately upon the closing of the Issuer's initial public offering and has no expiration date.

2. Shares held by Skyline Venture Partners V, L.P. ("SVP V"). Skyline Venture Management V, LLC ("LLC") is the general partner of SVP V and as such may be deemed to have voting and investment power with respect to the securities of SVP V. John G. Freund, a member of the Issuer's board of directors, together with Yasunori Kaneko, are the managing directors of LLC and each may be deemed to have voting and investment power with respect to the securities held by SVP V. Dr. Freund and Mr. Kaneko disclaim beneficial ownership of such securities, except to the extent of their pecuniary interest therein.

3. The Issuer's Series 6 Preferred Stock automatically converted into approximately 1.05878 shares of Issuer's common stock immediately upon the closing of the Issuer's initial public offering and has no expiration date.

4. Shares subject to the warrant are immediately exercisable. The warrant will expire in connection with the closing of the Issuer's initial public offering.

5. Immediately prior to the closing of the Issuer's initial public offering, SVP V exercised a warrant to purchase 39,421 shares of Series 5 Preferred Stock at an exercise price of $9.10 per share. The exercise price was paid on a net exercise cashless basis calculated using the Issuer's initial public offering price of $15.00, resulting in the Issuer withholding 23,904 of the warrant shares to pay the exercise price and issuing SVP V the remaining 15,517 shares.

Remarks:

	Skyline Venture Partners V, L.P., By: Skyline Venture Management V, LLC, Its: General Partner, By: /s/ Kerensa Kenny, Attorney-in-Fact	10/19/2018
	Skyline Venture Management V, LLC, By: /s/ Kerensa Kenny, Attorney-in-Fact	10/19/2018
	/s/ John G. Freund, /s/ Kerensa Kenny, Attorney-in-Fact	10/19/2018
	/s/ Yasunori Kaneko, /s/ Kerensa Kenny, Attorney-in-Fact	10/19/2018
	** Signature of Reporting Person	Date
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