Michelle Robertson

Insider

First SEC filing: Jan. 10, 2020 · Latest: Jan. 10, 2020

On this page

Insider at Companies where this person is a reporting insider.
Insider transactions Every share this person bought or sold, from Form 4 filings.
Derivatives Options and other derivative holdings reported by this person.
Initial holdings The stakes this person held when they first started reporting.
Compensation Executive pay disclosed in company proxy statements.

Insider at

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 29 non-open-market transactions below last 12 months, based on the transactions shown below

Price change vs current quote, split-adjusted for corporate actions since the filing — not benchmarked, not annualized, not size-weighted

29 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
May 21, 2026	VSTM	A	36,000	—	—	52,666 Direct	+216.01%	Acquired	(price as of 2026-08-20)
May 22, 2025	VSTM	A	12,500	—	—	12,500 Direct	—	Acquired	(price as of 2026-08-20)
May 22, 2025	VSTM	A	8,333	—	—	16,666 Direct	+100.00%	Acquired	(price as of 2026-08-20)
Feb. 18, 2025	GERN	A	110,000	—	—	110,000 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 18, 2025	GERN	A	656,000	—	—	656,000 Direct	—	Acquired	(price as of 2026-08-20)
June 18, 2024	VSTM	A	12,500	—	—	12,500 Direct	—	Acquired	(price as of 2026-08-20)
June 18, 2024	VSTM	A	8,333	—	—	8,333 Direct	—	Acquired	(price as of 2026-08-20)
June 6, 2024	GERN	A	250,000	—	—	250,000 Direct	—	Acquired	(price as of 2026-08-20)
March 11, 2024	VSTM	A	5,291	—	—	5,291 Direct	—	Acquired	(price as of 2026-08-20)
March 11, 2024	VSTM	D	5,291	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Feb. 14, 2024	GERN	A	850,000	—	—	850,000 Direct	—	Acquired	(price as of 2026-08-20)
Sept. 25, 2023	GERN	A	1,350,000	—	—	1,350,000 Direct	—	Acquired	(price as of 2026-08-20)
May 15, 2023	VSTM	A	62,500	—	—	62,500 Direct	—	Acquired	(price as of 2026-08-20)
May 11, 2023	EDIT	S	949	$9.87	$9,367	106,610 Direct	-0.88%	Disposed	-68.6% (price as of 2026-08-20)
March 3, 2023	EDIT	S	184	$8.89	$1,636	107,559 Direct	-0.17%	Disposed	-65.1% (price as of 2026-08-20)
March 2, 2023	EDIT	A	31,500	—	—	107,743 Direct	+41.32%	Acquired	(price as of 2026-08-20)
March 2, 2023	EDIT	A	94,500	—	—	94,500 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 13, 2023	EDIT	S	4,287	$9.67	$41,455	76,243 Direct	-5.32%	Disposed	-67.9% (price as of 2026-08-20)
Jan. 10, 2023	EDIT	S	1,752	$8.16	$14,296	80,530 Direct	-2.13%	Disposed	-62.0% (price as of 2026-08-20)
Dec. 5, 2022	EDIT	S	193	$10.23	$1,974	82,282 Direct	-0.23%	Disposed	-69.7% (price as of 2026-08-20)
Sept. 6, 2022	EDIT	S	192	$15.01	$2,882	82,475 Direct	-0.23%	Disposed	-79.3% (price as of 2026-08-20)
June 22, 2022	VSTM	A	62,500	—	—	62,500 Direct	—	Acquired	(price as of 2026-08-20)
June 3, 2022	EDIT	S	1,527	$11.54	$17,622	82,667 Direct	-1.81%	Disposed	-73.1% (price as of 2026-08-20)
May 12, 2022	VSTM	A	62,500	—	—	62,500 Direct	—	Acquired	(price as of 2026-08-20)
March 3, 2022	EDIT	S	767	$17.33	$13,292	84,194 Direct	-0.90%	Disposed	-82.1% (price as of 2026-08-20)
Feb. 10, 2022	EDIT	A	53,499	—	—	84,961 Direct	+170.04%	Acquired	(price as of 2026-08-20)
Feb. 10, 2022	EDIT	A	157,580	—	—	157,580 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 11, 2022	EDIT	S	1,744	$25.70	$44,821	31,462 Direct	-5.25%	Disposed	-87.9% (price as of 2026-08-20)
Dec. 22, 2021	EDIT	A	4,471	—	—	33,206 Direct	+15.56%	Acquired	(price as of 2026-08-20)
Nov. 15, 2021	VSTM	A	63,493	—	—	63,493 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 9, 2021	EDIT	M 10b5-1	2,500	—	—	115,000 Direct	-2.13%	Disposed	(price as of 2026-08-20)
Aug. 9, 2021	EDIT	S 10b5-1	2,500	$60.00	$150,000	28,735 Direct	-8.00%	Disposed	-94.8% (price as of 2026-08-20)
Aug. 9, 2021	EDIT	M 10b5-1	2,500	$30.65	$76,625	31,235 Direct	+8.70%	Acquired	-89.9% (price as of 2026-08-20)
June 28, 2021	EDIT	M 10b5-1	2,500	$30.65	$76,625	31,235 Direct	+8.70%	Acquired	-89.9% (price as of 2026-08-20)
June 28, 2021	EDIT	S 10b5-1	2,500	$50.00	$125,000	28,735 Direct	-8.00%	Disposed	-93.8% (price as of 2026-08-20)
June 28, 2021	EDIT	M 10b5-1	2,500	—	—	117,500 Direct	-2.08%	Disposed	(price as of 2026-08-20)
March 2, 2021	EDIT	A	32,197	—	—	32,197 Direct	—	Acquired	(price as of 2026-08-20)
March 2, 2021	EDIT	A	10,303	—	—	28,735 Direct	+55.90%	Acquired	(price as of 2026-08-20)
Jan. 12, 2021	EDIT	S	1,568	$78.27	$122,727	18,432 Direct	-7.84%	Disposed	-96.0% (price as of 2026-08-20)
Jan. 9, 2020	EDIT	A	120,000	—	—	120,000 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 9, 2020	EDIT	A	20,000	—	—	20,000 Direct	—	Acquired	(price as of 2026-08-20)

P = Open-market purchase · S = Sale · A = Grant/award · M = Option exercise · G = Gift · F = Tax withholding

Insider transactions are not a recommendation; sales are often driven by liquidity or tax reasons.

Derivative holdings (Form 4 Table II)

Options, RSUs and convertible securities reported on Form 4 Table II.

Date	Ticker	Security	Underlying	Exercise price	Expiration	Shares	A/D
May 22, 2025	VSTM	Stock Option (right to buy)	Common Stock (12,500)	$7.48	May 22, 2035	12,500	Acquired
Feb. 18, 2025	GERN	Restricted Stock Units	Common Stock (110,000)	—	—	110,000	Acquired
Feb. 18, 2025	GERN	Stock Option (right to buy)	Common Stock (656,000)	$2.63	Feb. 17, 2035	656,000	Acquired
June 18, 2024	VSTM	Stock Option (right to buy)	Common Stock (12,500)	$3.27	June 18, 2034	12,500	Acquired
June 6, 2024	GERN	Employee Stock Option (Right to Buy)	Common Stock (250,000)	$2.17	Sept. 24, 2033	250,000	Acquired
March 11, 2024	VSTM	Stock Option (right to buy)	Common Stock (5,291)	$11.44	March 11, 2034	5,291	Acquired
March 11, 2024	VSTM	Stock Option (right to buy)	Common Stock (5,291)	$37.32	Nov. 15, 2031	5,291	Disposed
Feb. 14, 2024	GERN	Employee Stock Option (Right to Buy)	Common Stock (850,000)	$2.10	Feb. 13, 2034	850,000	Acquired
Sept. 25, 2023	GERN	Employee Stock Option (right to buy)	Common Stock (1,350,000)	$2.17	Sept. 24, 2033	1,350,000	Acquired
May 15, 2023	VSTM	Stock Option (right to buy)	Common Stock (62,500)	$0.42	May 15, 2033	62,500	Acquired
March 2, 2023	EDIT	Stock Option (right to buy)	Common Stock (94,500)	$8.72	March 1, 2033	94,500	Acquired
June 22, 2022	VSTM	Stock Option (right to buy)	Common Stock (62,500)	$1.11	June 22, 2032	62,500	Acquired
May 12, 2022	VSTM	Stock Option (right to buy) [F1]	Common Stock (62,500)	$1.07	May 12, 2032	62,500	Acquired
Feb. 10, 2022	EDIT	Stock Option (right to buy)	Common Stock (157,580)	$17.29	Feb. 9, 2032	157,580	Acquired
Nov. 15, 2021	VSTM	Stock Option (right to buy)	Common Stock (63,493)	$3.11	Nov. 15, 2031	63,493	Acquired
Aug. 9, 2021	EDIT	Stock Option (right to buy)	Common Stock (2,500)	$30.65	Jan. 8, 2030	2,500	Disposed
June 28, 2021	EDIT	Stock Option (right to buy)	Common Stock (2,500)	$30.65	Jan. 8, 2030	2,500	Disposed
March 2, 2021	EDIT	Stock Option (right to buy)	Common Stock (32,197)	$45.69	March 1, 2031	32,197	Acquired
Jan. 9, 2020	EDIT	Stock Option (right to buy)	Common Stock (120,000)	$30.65	Jan. 8, 2030	120,000	Acquired

Exercise/conversion price is blank when not applicable (e.g. RSUs).

Initial ownership (Form 3) 1 holding

Securities held when first becoming an insider, per SEC Form 3.

Date	Ticker	Security	Shares	Ownership
Jan. 10, 2020	EDIT	No securities are beneficially owned	0	Direct

Compensation (DEF 14A)

Matched by name from proxy statements (DEF 14A) — verify against the filing.

GERN

CFO

Fiscal year	Salary	Bonus	Stock awards	Option awards	Non-equity incentive	Pension change	Other	Total
2023	$141,346	$126,194	—	$2,128,680	$67,006	—	$6,433	$2,469,659

EDIT

Fiscal year	Salary	Bonus	Stock awards	Option awards	Non-equity incentive	Pension change	Other	Total
2023	$303,464	—	$274,680	$823,799	—	—	$175,553	$1,577,496

Figures from the Summary Compensation Table of the company's proxy statement (DEF 14A). Compensation is not a recommendation.