Chirfi Guindo

Insider

First SEC filing: April 28, 2023 · Latest: June 5, 2026

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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) 5 sells (S) Net: $-8,151,300 + 72 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

72 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
Aug. 13, 2026	MRK	S	10,000	$135.00	$1,350,000	36,613 Direct	-21.45%	Disposed	11.4% (price as of 2026-08-20)
Aug. 6, 2026	MRK	S	15,000	$131.00	$1,965,000	46,613 Direct	-24.35%	Disposed	14.8% (price as of 2026-08-20)
June 3, 2026	BEAM	A	19,676	—	—	19,676 Direct	—	Acquired	(price as of 2026-08-20)
May 5, 2026	MRK	A	19,402	—	—	19,402 Direct	—	Acquired	(price as of 2026-08-20)
May 5, 2026	MRK	A	6,628	—	—	6,628 Direct	—	Acquired	(price as of 2026-08-20)
April 29, 2026	MRK	M	1,967	—	—	3,935 Direct	-33.33%	Disposed	(price as of 2026-08-20)
April 29, 2026	MRK	F	969	$110.03	$106,619	61,613 Direct	-1.55%	Disposed	36.7% (price as of 2026-08-20)
April 29, 2026	MRK	M	1,967	$110.03	$216,429	62,582 Direct	+3.25%	Acquired	36.7% (price as of 2026-08-20)
Feb. 12, 2026	MRK	S	10,000	$121.46	$1,214,600	60,615 Direct	-14.16%	Disposed	23.8% (price as of 2026-08-20)
Feb. 9, 2026	MRK	S	10,000	$118.41	$1,184,100	70,615 Direct	-12.40%	Disposed	27.0% (price as of 2026-08-20)
Feb. 5, 2026	MRK	S	20,000	$121.88	$2,437,600	80,615 Direct	-19.88%	Disposed	23.4% (price as of 2026-08-20)
Jan. 26, 2026	MRK	A	9,865	$107.40	$1,059,501	100,615 Direct	+10.87%	Acquired	40.0% (price as of 2026-08-20)
Aug. 4, 2025	MRK	M	36,903	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Aug. 4, 2025	MRK	F	18,175	$79.29	$1,441,096	89,234 Direct	-16.92%	Disposed	89.7% (price as of 2026-08-20)
Aug. 4, 2025	MRK	M	36,903	$79.29	$2,926,039	107,409 Direct	+52.34%	Acquired	89.7% (price as of 2026-08-20)
June 4, 2025	BEAM	A	33,662	—	—	33,662 Direct	—	Acquired	(price as of 2026-08-20)
April 29, 2025	MRK	A	26,867	—	—	26,867 Direct	—	Acquired	(price as of 2026-08-20)
April 29, 2025	MRK	A	5,902	—	—	5,902 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 27, 2025	MRK	A	28,158	$97.94	$2,757,795	69,144 Direct	+68.70%	Acquired	53.6% (price as of 2026-08-20)
Dec. 2, 2024	BEAM	A	39,086	—	—	39,086 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 5, 2024	MRK	M	36,901	—	—	36,903 Direct	-50.00%	Disposed	(price as of 2026-08-20)
Aug. 5, 2024	MRK	F	17,412	$115.20	$2,005,862	40,370 Direct	-30.13%	Disposed	30.6% (price as of 2026-08-20)
Aug. 5, 2024	MRK	M	36,901	$115.20	$4,250,995	57,782 Direct	+176.72%	Acquired	30.6% (price as of 2026-08-20)
April 30, 2024	MRK	A	29,297	—	—	29,297 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 3, 2023	MRK	M	36,901	—	—	73,804 Direct	-33.33%	Disposed	(price as of 2026-08-20)
Aug. 3, 2023	MRK	F	17,989	$105.70	$1,901,437	20,353 Direct	-46.92%	Disposed	42.3% (price as of 2026-08-20)
Aug. 3, 2023	MRK	M	36,901	$105.70	$3,900,436	38,342 Direct	+2560.79%	Acquired	42.3% (price as of 2026-08-20)
May 2, 2023	MRK	A	34,578	—	—	34,578 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 3, 2022	MRK	A	110,705	—	—	110,705 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 18, 2022	BIIB	J	2,851	—	—	9,668 Direct	-22.77%	Disposed	(price as of 2026-08-20)
Feb. 18, 2022	BIIB	M	1,981	—	—	12,519 Direct	-13.66%	Disposed	(price as of 2026-08-20)
Feb. 18, 2022	BIIB	F	879	$209.79	$184,405	7,364 Direct	-10.66%	Disposed	4.9% (price as of 2026-08-20)
Feb. 18, 2022	BIIB	M	1,981	—	—	8,243 Direct	+31.64%	Acquired	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	J	2,480	—	—	3,818 Direct	-39.38%	Disposed	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	M	1,336	—	—	6,298 Direct	-17.50%	Disposed	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	J	2,395	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	M	1,261	—	—	2,395 Direct	-34.49%	Disposed	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	F	1,189	$214.59	$255,148	6,262 Direct	-15.96%	Disposed	2.5% (price as of 2026-08-20)
Feb. 12, 2022	BIIB	F	593	$214.59	$127,252	7,451 Direct	-7.37%	Disposed	2.5% (price as of 2026-08-20)
Feb. 12, 2022	BIIB	M	1,336	—	—	8,044 Direct	+19.92%	Acquired	(price as of 2026-08-20)
Feb. 12, 2022	BIIB	F	560	$214.59	$120,170	6,708 Direct	-7.71%	Disposed	2.5% (price as of 2026-08-20)
Feb. 12, 2022	BIIB	M	1,261	—	—	7,268 Direct	+20.99%	Acquired	(price as of 2026-08-20)
Feb. 10, 2022	BIIB	A	9,090	—	—	9,090 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 19, 2022	BIIB	A	3,088	—	—	6,007 Direct	+105.79%	Acquired	(price as of 2026-08-20)
June 7, 2021	BIIB	S 10b5-1	3,087	$440.00	$1,358,280	2,919 Direct	-51.40%	Disposed	-50.0% (price as of 2026-08-20)
Feb. 18, 2021	BIIB	A	14,500	—	—	14,500 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	J	2,194	—	—	7,634 Direct	-22.32%	Disposed	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	M	1,622	—	—	9,828 Direct	-14.17%	Disposed	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	J	2,118	—	—	3,656 Direct	-36.68%	Disposed	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	M	1,534	—	—	5,774 Direct	-20.99%	Disposed	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	F	477	$278.03	$132,620	6,006 Direct	-7.36%	Disposed	-20.9% (price as of 2026-08-20)
Feb. 12, 2021	BIIB	F	463	$278.03	$128,728	6,483 Direct	-6.67%	Disposed	-20.9% (price as of 2026-08-20)
Feb. 12, 2021	BIIB	M	1,622	—	—	6,946 Direct	+30.47%	Acquired	(price as of 2026-08-20)
Feb. 12, 2021	BIIB	M	1,534	—	—	5,324 Direct	+40.47%	Acquired	(price as of 2026-08-20)
Dec. 1, 2020	BIIB	F	214	$243.16	$52,036	3,790 Direct	-5.34%	Disposed	-9.5% (price as of 2026-08-20)
Dec. 1, 2020	BIIB	J	693	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Dec. 1, 2020	BIIB	M	481	—	—	693 Direct	-40.97%	Disposed	(price as of 2026-08-20)
Dec. 1, 2020	BIIB	M	481	—	—	4,004 Direct	+13.65%	Acquired	(price as of 2026-08-20)
Dec. 1, 2020	BIIB	F	348	$243.16	$84,620	3,523 Direct	-8.99%	Disposed	-9.5% (price as of 2026-08-20)
Feb. 12, 2020	BIIB	A	11,450	—	—	11,450 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 12, 2020	BIIB	J	1,972	—	—	7,308 Direct	-21.25%	Disposed	(price as of 2026-08-20)
Feb. 12, 2020	BIIB	M	1,680	—	—	9,280 Direct	-15.33%	Disposed	(price as of 2026-08-20)
Feb. 12, 2020	BIIB	F	504	$331.76	$167,207	3,871 Direct	-11.52%	Disposed	-33.7% (price as of 2026-08-20)
Feb. 12, 2020	BIIB	M	1,680	—	—	4,375 Direct	+62.34%	Acquired	(price as of 2026-08-20)
Dec. 1, 2019	BIIB	J	625	—	—	1,174 Direct	-34.74%	Disposed	(price as of 2026-08-20)
Dec. 1, 2019	BIIB	M	543	—	—	1,799 Direct	-23.19%	Disposed	(price as of 2026-08-20)
Dec. 1, 2019	BIIB	F	160	$299.81	$47,970	2,695 Direct	-5.60%	Disposed	-26.6% (price as of 2026-08-20)
Dec. 1, 2019	BIIB	M	543	—	—	2,855 Direct	+23.49%	Acquired	(price as of 2026-08-20)
Dec. 1, 2019	BIIB	F	231	$299.81	$69,256	2,312 Direct	-9.08%	Disposed	-26.6% (price as of 2026-08-20)
Feb. 12, 2019	BIIB	A	10,960	—	—	10,960 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 1, 2018	BIIB	J	566	—	—	2,342 Direct	-19.46%	Disposed	(price as of 2026-08-20)
Dec. 1, 2018	BIIB	M	602	—	—	2,908 Direct	-17.15%	Disposed	(price as of 2026-08-20)
Dec. 1, 2018	BIIB	F	178	$333.72	$59,402	2,543 Direct	-6.54%	Disposed	-34.1% (price as of 2026-08-20)
Dec. 1, 2018	BIIB	M	602	—	—	2,721 Direct	+28.41%	Acquired	(price as of 2026-08-20)
Dec. 1, 2018	BIIB	F	231	$333.72	$77,089	2,119 Direct	-9.83%	Disposed	-34.1% (price as of 2026-08-20)
Dec. 1, 2017	BIIB	A	3,510	—	—	3,510 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 1, 2017	BIIB	A	1,755	—	—	1,755 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 1, 2017	BIIB	A	2,350	—	—	2,350 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
June 3, 2026	BEAM	Stock Option (Right to Buy)	Common Stock (19,676)	$29.55	June 3, 2036	19,676	Acquired
May 5, 2026	MRK	Stock Option (Right to Buy)	Common Stock (19,402)	$113.15	May 4, 2036	19,402	Acquired
May 5, 2026	MRK	Restricted Stock Unit	Common Stock (6,628)	—	May 5, 2029	6,628	Acquired
April 29, 2026	MRK	Restricted Stock Unit	Common Stock (1,967)	—	April 29, 2028	1,967	Disposed
Aug. 4, 2025	MRK	Restricted Stock Unit	Common Stock (36,903)	—	Aug. 3, 2025	36,903	Disposed
June 4, 2025	BEAM	Stock Option (Right to Buy)	Common Stock (33,662)	$17.15	June 4, 2025	33,662	Acquired
April 29, 2025	MRK	Stock Option (Right to Buy)	Common Stock (26,867)	$84.71	April 28, 2035	26,867	Acquired
April 29, 2025	MRK	Restricted Stock Unit	Common Stock (5,902)	—	April 29, 2028	5,902	Acquired
Dec. 2, 2024	BEAM	Stock Option (Right to Buy)	Common Stock (39,086)	$28.30	Dec. 2, 2034	39,086	Acquired
Aug. 5, 2024	MRK	Restricted Stock Unit	Common Stock (36,901)	—	Aug. 3, 2025	36,901	Disposed
April 30, 2024	MRK	Stock Option (Right to Buy)	Common Stock (29,297)	$129.22	April 29, 2034	29,297	Acquired
Aug. 3, 2023	MRK	Restricted Stock Unit	Common Stock (36,901)	—	Aug. 3, 2025	36,901	Disposed
May 2, 2023	MRK	Stock Option (Right to Buy)	Common Stock (34,578)	$117.89	May 1, 2033	34,578	Acquired
Aug. 3, 2022	MRK	Restricted Stock Unit	Common Stock (110,705)	—	Aug. 3, 2025	110,705	Acquired
Feb. 18, 2022	BIIB	Restricted Stock Unit	Common Stock (2,851)	$0.00	Feb. 18, 2024	2,851	Disposed
Feb. 18, 2022	BIIB	Restricted Stock Unit	Common Stock (1,981)	$0.00	Feb. 18, 2024	1,981	Disposed
Feb. 12, 2022	BIIB	Restricted Stock Unit	Common Stock (2,480)	$0.00	Feb. 12, 2023	2,480	Disposed
Feb. 12, 2022	BIIB	Restricted Stock Unit	Common Stock (1,336)	$0.00	Feb. 12, 2023	1,336	Disposed
Feb. 12, 2022	BIIB	Restricted Stock Unit	Common Stock (2,395)	$0.00	Feb. 12, 2022	2,395	Disposed
Feb. 12, 2022	BIIB	Restricted Stock Unit	Common Stock (1,261)	$0.00	Feb. 12, 2022	1,261	Disposed
Feb. 10, 2022	BIIB	Restricted Stock Unit	Common Stock (9,090)	$0.00	Feb. 10, 2025	9,090	Acquired
Feb. 18, 2021	BIIB	Restricted Stock Unit	Common Stock (14,500)	$0.00	Feb. 18, 2024	14,500	Acquired
Feb. 12, 2021	BIIB	Restricted Stock Unit	Common Stock (2,194)	$0.00	Feb. 12, 2023	2,194	Disposed
Feb. 12, 2021	BIIB	Restricted Stock Unit	Common Stock (1,622)	$0.00	Feb. 12, 2023	1,622	Disposed
Feb. 12, 2021	BIIB	Restricted Stock Unit	Common Stock (2,118)	$0.00	Feb. 12, 2022	2,118	Disposed
Feb. 12, 2021	BIIB	Restricted Stock Unit	Common Stock (1,534)	$0.00	Feb. 12, 2022	1,534	Disposed
Dec. 1, 2020	BIIB	Restricted Stock Unit	Common Stock (693)	$0.00	Dec. 1, 2020	693	Disposed
Dec. 1, 2020	BIIB	Restricted Stock Unit	Common Stock (481)	$0.00	Dec. 1, 2020	481	Disposed
Feb. 12, 2020	BIIB	Restricted Stock Unit	Common Stock (11,450)	$0.00	Feb. 12, 2023	11,450	Acquired
Feb. 12, 2020	BIIB	Restricted Stock Unit	Common Stock (1,972)	$0.00	Feb. 12, 2022	1,972	Disposed
Feb. 12, 2020	BIIB	Restricted Stock Unit	Common Stock (1,680)	$0.00	Feb. 12, 2022	1,680	Disposed
Dec. 1, 2019	BIIB	Restricted Stock Unit	Common Stock (625)	$0.00	Dec. 1, 2020	625	Disposed
Dec. 1, 2019	BIIB	Restricted Stock Unit	Common Stock (543)	$0.00	Dec. 1, 2020	543	Disposed
Feb. 12, 2019	BIIB	Restricted Stock Unit	Common Stock (10,960)	$0.00	Feb. 12, 2022	10,960	Acquired
Dec. 1, 2018	BIIB	Restricted Stock Unit	Common Stock (566)	$0.00	Dec. 1, 2020	566	Disposed
Dec. 1, 2018	BIIB	Restricted Stock Unit	Common Stock (602)	$0.00	Dec. 1, 2020	602	Disposed
Dec. 1, 2017	BIIB	Restricted Stock Unit	Common Stock (3,510)	$0.00	Dec. 1, 2020	3,510	Acquired
Dec. 1, 2017	BIIB	Restricted Stock Unit	Common Stock (1,755)	$0.00	Dec. 1, 2020	1,755	Acquired

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

Initial ownership (Form 3) 5 holdings

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

Date	Ticker	Security	Shares	Ownership
April 28, 2023	MRK	Common Stock	1,399	Direct
April 28, 2023	MRK	Common Stock-401(k) Plan	50	Indirect
July 8, 2022	MRK	Common Stock	2	Direct
July 8, 2022	MRK	Common Stock-401(k) Plan	50	Indirect
Nov. 16, 2017	BIIB	Common Stock	0	Direct

Compensation (DEF 14A)

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

BIIB

Fiscal year	Salary	Bonus	Stock awards	Option awards	Non-equity incentive	Pension change	Other	Total
2022	$372,818	—	—	—	—	—	$92,951	$5,382,348
2021	$618,508	—	$4,476,969	—	$586,138	—	$69,047	$5,750,662
2020	$562,819	—	$3,961,285	—	$527,970	—	$80,721	$5,132,795

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