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* Spring Mountain Capital G.P., LLC (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol IsoPlexis Corp [ ISO ]	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) 10/12/2021
	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	10/12/2021		C		894,128(1)(5)	A	(1)	894,128	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		338,959(1)(6)	A	(1)	1,233,087	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		630,209(1)(7)	A	(1)	1,863,296	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		739,033(1)(8)	A	(1)	2,602,329	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		689,267(1)(9)	A	(1)	3,291,596	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		435,136(1)(10)	A	(1)	3,726,732	I	By SMC Growth Capital Partners II, LP(2)
Common Stock	10/12/2021		C		744,083(1)(11)	A	(1)	744,083	I	By SMC Private Equity Holdings, LP(3)
Common Stock	10/12/2021		C		459,781(1)(12)	A	(1)	1,203,864	I	By SMC Private Equity Holdings, LP(3)
Common Stock	10/12/2021		C		415,337(1)(13)	A	(1)	1,619,201	I	By SMC Private Equity Holdings, LP(3)
Common Stock	10/12/2021		C		215,950(1)(14)	A	(1)	1,835,151	I	By SMC Private Equity Holdings, LP(3)
Common Stock	10/12/2021		C		435,136(1)(15)	A	(1)	2,270,287	I	By SMC Private Equity Holdings, LP(3)
Common Stock	10/12/2021		C		67,642(1)(16)	A	(1)	67,642	I	By SMC Holdings II, LP(4)

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
Series A Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			107,604	(1)	(1)	Common Stock	860,832(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series A-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			39,726	(1)	(1)	Common Stock	317,808(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series A-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			87,398	(1)	(1)	Common Stock	699,184(1)	$0.00	0	I	By SMC Private Equity Holdings, LP(3)
Series A-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			7,945	(1)	(1)	Common Stock	63,560(1)	$0.00	0	I	By SMC Holdings II, LP(4)
Series B Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			73,571	(1)	(1)	Common Stock	588,568(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series B Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			53,480	(1)	(1)	Common Stock	427,840(1)	$0.00	0	I	By SMC Private Equity Holdings, LP(3)
Series B-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			84,347	(1)	(1)	Common Stock	674,776(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series B-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			47,403	(1)	(1)	Common Stock	379,224(1)	$0.00	0	I	By SMC Private Equity Holdings, LP(3)
Series C Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			78,999	(1)	(1)	Common Stock	631,992(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series C Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			24,833	(1)	(1)	Common Stock	198,664(1)	$0.00	0	I	By SMC Private Equity Holdings, LP(3)
Series C-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			51,522	(1)	(1)	Common Stock	412,176(1)	$0.00	0	I	By SMC Growth Capital Partners II, LP(2)
Series C-2 Redeemable Convertible Preferred Stock	(1)	10/12/2021		C			51,522	(1)	(1)	Common Stock	412,176(1)	$0.00	0	I	By SMC Private Equity Holdings, LP(3)

1. Name and Address of Reporting Person* Spring Mountain Capital G.P., LLC (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Growth Capital II GP, LLC (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Growth Capital Partners II, LP (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Private Equity Holdings GP, LLC (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Private Equity Holdings, LP (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Holdings II G.P., LLC (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* SMC Holdings II, LP (Last) (First) (Middle) 65 EAST 55TH STREET, 33RD FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* Ho Gregory P. (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

1. Name and Address of Reporting Person* Steffens John (Last) (First) (Middle) 650 MADISON AVENUE, 20TH FLOOR (Street) NEW YORK NY 10022 (City) (State) (Zip)

Explanation of Responses:

1. Shares of Series A Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer, Series A-2 Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer, Series B Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer, Series B-2 Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer, Series C Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer and Series C-2 Redeemable Convertible Preferred Stock, par value $0.001, of the Issuer (collectively, the "Preferred Stock") were convertible on a one-for-eight basis into shares of Common Stock of the Issuer at the option of the holder at any time and automatically converted upon the closing of the Issuer's initial public offering. The Preferred Stock had no expiration date.

2. The securities are directly held by SMC Growth Capital Partners II, LP ("GCII"). SMC Growth Capital II GP, LLC, a Delaware limited liability company ("GCII GP"), is the general partner of GCII, and Spring Mountain Capital G.P., LLC, a Delaware limited liability company ("SMC GP"), is the managing member of GCII GP. John L. Steffens and Gregory P. Ho each serves as a managing member of SMC GP. Each of GCII GP, SMC GP, Mr. Steffens and Mr. Ho may be deemed to indirectly hold the securities held by GCII. GCII holds voting and dispositive power over the securities it holds. Each of Mr. Steffens, Mr. Ho, GCII GP and SMC GP disclaims beneficial ownership of these securities, except to the extent of their respective pecuniary interests therein.

3. The securities are directly held by SMC Private Equity Holdings, LP ("PEH"). SMC Private Equity Holdings G.P., LLC, a Delaware limited liability company ("PEH GP"), is the general partner of PEH, and SMC GP is the managing member of PEH GP. Mr. Steffens and Mr. Ho each serves as a managing member of SMC GP. Each of PEH GP, SMC GP, Mr. Steffens and Mr. Ho may be deemed to indirectly hold the securities held by PEH. PEH holds voting and dispositive power over the securities it holds. Each of Mr. Steffens, Mr. Ho, PEH GP and SMC GP disclaims beneficial ownership of these securities, except to the extent of their respective pecuniary interests therein.

4. The securities are directly held by SMC Holdings II, LP ("Holdings"). SMC Holdings II G.P., LLC, a Delaware limited liability company ("Holdings GP"), is the general partner of Holdings. Mr. Steffens and Mr. Ho each serves as a managing member of Holdings GP. Each of Holdings GP, Mr. Steffens and Mr. Ho may be deemed to indirectly hold the securities held by Holdings. Holdings holds voting and dispositive power over the securities it holds. Each of Mr. Steffens, Mr. Ho and Holdings GP disclaims beneficial ownership of these securities, except to the extent of their respective pecuniary interests therein.

5. Includes 33,296 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

6. Includes 21,151 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

7. Includes 41,641 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

8. Includes 64,257 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

9. Includes 57,275 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

10. Includes 22,960 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

11. Includes 44,899 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

12. Includes 31,941 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

13. Includes 36,113 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

14. Includes 17,286 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

15. Includes 22,960 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

16. Includes 4,082 shares of Common Stock issued per dividends accrued to but not including October 12, 2021.

	Spring Mountain Capital G.P., LLC, by Gregory P. Ho, as Managing Member /s/Gregory P. Ho	10/14/2021
	SMC Growth Capital II GP, LLC, by Spring Mountain Capital G.P., LLC, as Managing Member /s/Gregory P. Ho	10/14/2021
	SMC Growth Capital Partners II, LP, by SMC Growth Capital II GP, LLC, as its general partner /s/Gregory P. Ho	10/14/2021
	SMC Private Equity Holdings G.P., LLC, by Spring Mountain Capital G.P., LLC, as Managing Member /s/Gregory P. Ho	10/14/2021
	SMC Private Equity Holdings, LP, by SMC Private Equity Holdings G.P., as its general partner /s/Gregory P. Ho	10/14/2021
	SMC Holdings II G.P., LLC, by Gregory P. Ho, as Managing Member /s/Gregory P. Ho	10/14/2021
	SMC Holdings II, LP, by SMC Holdings II G.P., LLC, as its general partner /s/Gregory P. Ho	10/14/2021
	Gregory P. Ho /s/Gregory P. Ho	10/14/2021
	John L. Steffens /s/John L. Steffens	10/14/2021
	** Signature of Reporting Person	Date
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* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
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