Arthur H Amron

Insider

First SEC filing: June 12, 2026 · Latest: June 12, 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.

Insider at

Insider transactions

2 buys (P) 0 sells (S) Net: $14,610 + 35 non-open-market transactions below Avg return of open purchases vs now: -4.0% 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

35 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
Aug. 12, 2026	NEPH	A	2,418	—	—	140,874 Direct	+1.75%	Acquired	(price as of 2026-08-20)
June 12, 2026	TUSK	P	2,000	$3.28	$6,560	67,135 Direct	+3.07%	Acquired	-4.9% (price as of 2026-08-20)
June 11, 2026	TUSK	P	2,500	$3.22	$8,050	65,135 Direct	+3.99%	Acquired	-3.1% (price as of 2026-08-20)
May 11, 2026	NEPH	A	3,574	—	—	138,456 Direct	+2.65%	Acquired	(price as of 2026-08-20)
March 16, 2026	NEPH	A	3,610	—	—	134,882 Direct	+2.75%	Acquired	(price as of 2026-08-20)
Nov. 10, 2025	NEPH	A	5,391	—	—	131,272 Direct	+4.28%	Acquired	(price as of 2026-08-20)
Jan. 1, 2025	NEPH	A	7,050	—	—	7,050 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 1, 2025	NEPH	A	22,418	—	—	125,881 Direct	+21.67%	Acquired	(price as of 2026-08-20)
May 30, 2024	NEPH	P	3,000	$2.24	$6,720	103,463 Direct	+2.99%	Acquired	110.9% (price as of 2026-08-20)
May 28, 2024	NEPH	P	2,000	$2.22	$4,440	100,463 Direct	+2.03%	Acquired	112.8% (price as of 2026-08-20)
May 14, 2024	NEPH	A	7,323	—	—	7,323 Direct	—	Acquired	(price as of 2026-08-20)
March 13, 2024	NEPH	J	91,463	—	—	98,463 Direct	+1306.61%	Acquired	(price as of 2026-08-20)
March 12, 2024	NEPH	P	7,000	$2.45	$17,150	7,000 Direct	—	Acquired	92.9% (price as of 2026-08-20)
Dec. 13, 2023	NEPH	A	9,291	—	—	9,291 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 5, 2023	NEPH	A	27,613	—	—	27,613 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 5, 2023	NEPH	A	7,080	—	—	7,080 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 6, 2021	NEPH	A	3,666	—	—	3,666 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 6, 2021	NEPH	A	6,850	—	—	6,850 Direct	—	Acquired	(price as of 2026-08-20)
July 2, 2020	TUSK	A	86,957	—	—	86,957 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 16, 2019	NEPH	A	3,448	—	—	3,448 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 16, 2019	NEPH	A	5,568	—	—	5,568 Direct	—	Acquired	(price as of 2026-08-20)
June 5, 2019	TUSK	A	10,493	—	—	10,493 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 25, 2019	TUSK	A	1,549	—	—	1,549 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 19, 2018	NEPH	A	46,457	—	—	46,457 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 14, 2018	NEPH	A	47,673	—	—	47,673 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 20, 2017	NEPH	A	40,284	—	—	40,284 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 20, 2017	NEPH	A	73,864	—	—	73,864 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 24, 2016	NEPH	A	33,880	—	—	33,880 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 24, 2016	NEPH	A	73,864	—	—	73,864 Direct	—	Acquired	(price as of 2026-08-20)
Sept. 9, 2015	NEPH	A	58,240	—	—	58,240 Direct	—	Acquired	(price as of 2026-08-20)
Nov. 6, 2014	NEPH	A	25,395	—	—	25,395 Direct	—	Acquired	(price as of 2026-08-20)
March 26, 2014	NEPH	A	26,598	—	—	26,598 Direct	—	Acquired	(price as of 2026-08-20)
Dec. 31, 2013	NEPH	A	19,733	—	—	19,733 Direct	—	Acquired	(price as of 2026-08-20)
Aug. 20, 2013	NEPH	A	5,417	—	—	28,763 Direct	+23.20%	Acquired	(price as of 2026-08-20)
May 23, 2013	NEPH	A	23,346	—	—	23,346 Direct	—	Acquired	(price as of 2026-08-20)
May 23, 2013	NEPH	A	10,000	—	—	10,000 Direct	—	Acquired	(price as of 2026-08-20)
Feb. 16, 2012	NEPH	A	10,000	—	—	10,000 Direct	—	Acquired	(price as of 2026-08-20)
March 24, 2011	NEPH	A	32,000	—	—	32,000 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 8, 2010	NEPH	A	20,000	—	—	20,000 Direct	—	Acquired	(price as of 2026-08-20)
Nov. 30, 2007	NEPH	A	15,000	—	—	15,000 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
Jan. 1, 2025	NEPH	Stock Option (Right to Buy)	Common Stock (7,050)	$1.47	Jan. 1, 2035	7,050	Acquired
May 14, 2024	NEPH	Stock Option (Right to Buy)	Common Stock (7,323)	$2.14	May 14, 2034	7,323	Acquired
Jan. 5, 2023	NEPH	Stock Option (Right to Buy)	Common Stock (7,080)	$1.07	Jan. 5, 2033	7,080	Acquired
Jan. 6, 2021	NEPH	Stock Option (Right to Buy)	Common Stock (6,850)	$8.06	Jan. 6, 2031	6,850	Acquired
Dec. 16, 2019	NEPH	Stock Option (Right to Buy)	Common Stock (5,568)	$8.57	Dec. 16, 2029	5,568	Acquired
Dec. 19, 2018	NEPH	Stock Option (Right to Buy)	Common Stock (46,457)	$0.65	Dec. 19, 2028	46,457	Acquired
Dec. 20, 2017	NEPH	Non-Qualified Stock Option	Common Stock (40,284)	$0.50	Dec. 27, 2027	40,284	Acquired
Aug. 24, 2016	NEPH	Non-Qualified Stock Option	Common Stock (33,880)	$0.40	Aug. 24, 2026	33,880	Acquired
March 26, 2014	NEPH	Non Qualiffied Stock Option (right to buy)	Common Stock (26,598)	$0.46	March 26, 2024	26,598	Acquired
May 23, 2013	NEPH	Non-Qualified Stock Option (right to buy)	Common Stock (10,000)	$0.71	May 23, 2023	10,000	Acquired
Feb. 16, 2012	NEPH	Non-qualified stock option (right to buy)	Common Stock (10,000)	$0.83	Feb. 16, 2022	10,000	Acquired
March 24, 2011	NEPH	Non-qualified stock option (right to buy)	Common Stock (32,000)	$0.51	March 24, 2021	32,000	Acquired
Jan. 8, 2010	NEPH	Non-qualified stock option (right to buy)	Common Stock (20,000)	$0.95	Jan. 8, 2020	20,000	Acquired
Nov. 30, 2007	NEPH	Non-qualified stock option (right to buy)	Common Stock (15,000)	$0.80	Nov. 30, 2017	15,000	Acquired

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