JACKSON MARTIN F

Activist

First SEC filing: Nov. 24, 2025 · Latest: Nov. 24, 2025

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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.

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 46 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

46 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D
June 30, 2026	SEM	J	2,634	—	—	0 Indirect	-100.00%	Disposed
June 30, 2026	SEM	J	2,634	—	—	0 Indirect	-100.00%	Disposed
June 30, 2026	SEM	J	2,634	—	—	0 Indirect	-100.00%	Disposed
June 30, 2026	SEM	J	2,634	—	—	0 Indirect	-100.00%	Disposed
June 30, 2026	SEM	J	1,383,421	—	—	0 Direct	-100.00%	Disposed
Aug. 1, 2025	SEM	F	29,460	$12.57	$370,312	1,383,421 Direct	-2.09%	Disposed
July 29, 2025	SEM	A	150,000	—	—	1,412,881 Direct	+11.88%	Acquired
Nov. 5, 2024	SEM	F	42,422	$37.21	$1,578,523	1,262,881 Direct	-3.25%	Disposed
Aug. 3, 2024	SEM	F	53,028	$34.18	$1,812,497	1,305,303 Direct	-3.90%	Disposed
Aug. 1, 2024	SEM	F	18,648	$39.18	$730,629	1,358,331 Direct	-1.35%	Disposed
April 30, 2024	SEM	A	138,000	—	—	1,376,979 Direct	+11.14%	Acquired
Aug. 1, 2023	SEM	F	22,095	$29.92	$661,082	1,088,979 Direct	-1.99%	Disposed
Aug. 1, 2023	SEM	A	150,000	—	—	1,238,979 Direct	+13.77%	Acquired
July 28, 2023	SEM	F	61,814	$30.03	$1,856,274	1,111,074 Direct	-5.27%	Disposed
Aug. 1, 2022	SEM	A	150,000	—	—	1,172,888 Direct	+14.66%	Acquired
July 30, 2022	SEM	F	66,270	$29.62	$1,962,917	1,022,888 Direct	-6.08%	Disposed
July 30, 2022	SEM	F	66,270	$29.62	$1,962,917	1,022,888 Direct	-6.08%	Disposed
Aug. 3, 2021	SEM	A	120,000	—	—	1,089,158 Direct	+12.38%	Acquired
July 31, 2021	SEM	F	66,270	$39.45	$2,614,352	969,158 Direct	-6.40%	Disposed
June 16, 2021	SEM	S	100,000	$42.61	$4,261,000	1,035,428 Direct	-8.81%	Disposed
May 28, 2021	SEM	S	50,000	$40.07	$2,003,500	1,135,428 Direct	-4.22%	Disposed
May 27, 2021	SEM	S	100,000	$40.19	$4,019,000	1,185,428 Direct	-7.78%	Disposed
May 26, 2021	SEM	S	100,000	$40.15	$4,015,000	1,285,428 Direct	-7.22%	Disposed
May 24, 2021	SEM	J	250,000	—	—	1,385,428 Direct	-15.29%	Disposed
Aug. 2, 2020	SEM	F	66,270	$19.04	$1,261,781	1,635,428 Direct	-3.89%	Disposed
July 28, 2020	SEM	A	150,000	—	—	1,701,698 Direct	+9.67%	Acquired
June 4, 2020	SEM	S	50,255	$17.11	$859,863	1,551,698 Direct	-3.14%	Disposed
June 3, 2020	SEM	S	49,745	$17.08	$849,645	1,601,953 Direct	-3.01%	Disposed
Aug. 3, 2019	SEM	F	66,270	$15.78	$1,045,741	1,651,698 Direct	-3.86%	Disposed
July 30, 2019	SEM	A	150,000	—	—	1,717,968 Direct	+9.57%	Acquired
Nov. 5, 2018	SEM	D	50,000	$19.33	$966,500	1,567,968 Direct	-3.09%	Disposed
Nov. 5, 2018	SEM	D	50,000	$19.30	$965,000	1,617,968 Direct	-3.00%	Disposed
Aug. 5, 2018	SEM	F	66,270	$20.15	$1,335,340	1,667,968 Direct	-3.82%	Disposed
July 31, 2018	SEM	A	150,000	—	—	1,734,238 Direct	+9.47%	Acquired
Dec. 22, 2017	SEM	S	61,949	$17.05	$1,056,230	1,584,238 Direct	-3.76%	Disposed
Dec. 21, 2017	SEM	S	71,757	$17.05	$1,223,457	1,646,187 Direct	-4.18%	Disposed
Dec. 20, 2017	SEM	S	323	$17.05	$5,507	1,717,944 Direct	-0.02%	Disposed
Dec. 13, 2017	SEM	S	72,334	$17.06	$1,234,018	1,718,267 Direct	-4.04%	Disposed
Dec. 12, 2017	SEM	S	84,269	$17.06	$1,437,629	1,790,601 Direct	-4.49%	Disposed
Aug. 6, 2017	SEM	F	46,790	$17.15	$802,448	1,874,870 Direct	-2.43%	Disposed
Aug. 2, 2017	SEM	A	150,000	—	—	1,921,660 Direct	+8.47%	Acquired
Aug. 3, 2016	SEM	A	150,000	—	—	1,771,660 Direct	+9.25%	Acquired
Aug. 5, 2015	SEM	A	150,000	—	—	1,621,660 Direct	+10.19%	Acquired
Aug. 6, 2014	SEM	A	100,000	—	—	1,471,660 Direct	+7.29%	Acquired
Oct. 30, 2013	SEM	A	40,000	—	—	1,371,660 Direct	+3.00%	Acquired
Oct. 30, 2012	SEM	A	35,000	—	—	1,331,660 Direct	+2.70%	Acquired
Dec. 15, 2011	SEM	A	35,000	—	—	1,296,660 Direct	+2.77%	Acquired
Sept. 30, 2009	SEM	C	150,693	—	—	1,261,660 Direct	+13.56%	Acquired
Sept. 30, 2009	SEM	C	1,554	—	—	2,634 Indirect	+143.89%	Acquired
Sept. 30, 2009	SEM	C	1,554	—	—	2,634 Indirect	+143.89%	Acquired
Sept. 30, 2009	SEM	C	1,554	—	—	2,634 Indirect	+143.89%	Acquired
Sept. 30, 2009	SEM	C	1,554	—	—	2,634 Indirect	+143.89%	Acquired
Sept. 30, 2009	SEM	C	51,926	—	—	0 Direct	-100.00%	Disposed
Sept. 30, 2009	SEM	C	535	—	—	0 Indirect	-100.00%	Disposed
Sept. 30, 2009	SEM	C	535	—	—	0 Indirect	-100.00%	Disposed
Sept. 30, 2009	SEM	C	535	—	—	0 Indirect	-100.00%	Disposed
Sept. 30, 2009	SEM	C	535	—	—	0 Indirect	-100.00%	Disposed

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
Sept. 30, 2009	SEM	Participating Preferred Stock	Common Stock (150,693)	—	—	51,926	Disposed
Sept. 30, 2009	SEM	Participating Preferred Stock	Common Stock (1,554)	—	—	535	Disposed
Sept. 30, 2009	SEM	Participating Preferred Stock	Common Stock (1,554)	—	—	535	Disposed
Sept. 30, 2009	SEM	Participating Preferred Stock	Common Stock (1,554)	—	—	535	Disposed
Sept. 30, 2009	SEM	Participating Preferred Stock	Common Stock (1,554)	—	—	535	Disposed

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

Initial ownership (Form 3) 10 holdings

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

Date	Ticker	Security	Shares	Ownership
Sept. 24, 2009	SEM	Common Stock	1,110,967	Direct
Sept. 24, 2009	SEM	Common Stock	1,080	Indirect
Sept. 24, 2009	SEM	Common Stock	1,080	Indirect
Sept. 24, 2009	SEM	Common Stock	1,080	Indirect
Sept. 24, 2009	SEM	Common Stock	1,080	Indirect
Sept. 24, 2009	SEM	Participating Preferred Stock→ Common Stock	—	Direct
Sept. 24, 2009	SEM	Participating Preferred Stock→ Common Stock	—	Indirect
Sept. 24, 2009	SEM	Participating Preferred Stock→ Common Stock	—	Indirect
Sept. 24, 2009	SEM	Participating Preferred Stock→ Common Stock	—	Indirect
Sept. 24, 2009	SEM	Participating Preferred Stock→ Common Stock	—	Indirect