Donald C Winter

Insider

First SEC filing: Sept. 11, 2015 · Latest: Sept. 11, 2015

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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.

Insider at

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 71 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

71 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
July 2, 2018	MTX	A	297	—	—	12,998 Direct	+2.34%	Acquired	(price as of 2026-08-20)
June 14, 2018	MTX	A	8	—	—	12,701 Direct	+0.06%	Acquired	(price as of 2026-08-20)
May 16, 2018	MTX	A	1,381	—	—	12,693 Direct	+12.21%	Acquired	(price as of 2026-08-20)
May 16, 2018	MTX	A	1,344	—	—	12,655 Direct	+11.88%	Acquired	(price as of 2026-08-20)
April 2, 2018	MTX	A	346	—	—	11,311 Direct	+3.16%	Acquired	(price as of 2026-08-20)
March 8, 2018	MTX	A	8	—	—	10,966 Direct	+0.07%	Acquired	(price as of 2026-08-20)
Jan. 2, 2018	MTX	A	324	—	—	10,958 Direct	+3.05%	Acquired	(price as of 2026-08-20)
Dec. 8, 2017	MTX	A	8	—	—	10,635 Direct	+0.08%	Acquired	(price as of 2026-08-20)
Oct. 2, 2017	MTX	A	310	—	—	10,627 Direct	+3.00%	Acquired	(price as of 2026-08-20)
Sept. 7, 2017	MTX	A	8	—	—	10,317 Direct	+0.08%	Acquired	(price as of 2026-08-20)
July 3, 2017	MTX	A	305	—	—	10,308 Direct	+3.05%	Acquired	(price as of 2026-08-20)
June 9, 2017	MTX	A	7	—	—	10,004 Direct	+0.07%	Acquired	(price as of 2026-08-20)
May 17, 2017	MTX	A	1,381	—	—	9,997 Direct	+16.03%	Acquired	(price as of 2026-08-20)
April 3, 2017	MTX	A	298	—	—	8,616 Direct	+3.58%	Acquired	(price as of 2026-08-20)
March 9, 2017	MTX	A	6	—	—	8,317 Direct	+0.07%	Acquired	(price as of 2026-08-20)
Jan. 3, 2017	MTX	A	289	—	—	8,312 Direct	+3.60%	Acquired	(price as of 2026-08-20)
Dec. 9, 2016	MTX	A	5	—	—	8,022 Direct	+0.06%	Acquired	(price as of 2026-08-20)
Dec. 9, 2016	MTX	A	5	—	—	8,022 Direct	+0.06%	Acquired	(price as of 2026-08-20)
Oct. 3, 2016	MTX	A	323	—	—	8,017 Direct	+4.20%	Acquired	(price as of 2026-08-20)
Sept. 8, 2016	MTX	A	6	—	—	7,695 Direct	+0.08%	Acquired	(price as of 2026-08-20)
July 1, 2016	MTX	A	392	—	—	7,689 Direct	+5.37%	Acquired	(price as of 2026-08-20)
June 9, 2016	MTX	A	6	—	—	7,297 Direct	+0.08%	Acquired	(price as of 2026-08-20)
May 11, 2016	MTX	A	1,496	—	—	7,291 Direct	+25.82%	Acquired	(price as of 2026-08-20)
April 1, 2016	MTX	A	394	—	—	5,796 Direct	+7.29%	Acquired	(price as of 2026-08-20)
March 10, 2016	MTX	A	5	—	—	5,402 Direct	+0.09%	Acquired	(price as of 2026-08-20)
Jan. 4, 2016	MTX	A	518	—	—	5,396 Direct	+10.62%	Acquired	(price as of 2026-08-20)
Dec. 10, 2015	MTX	A	4	—	—	4,878 Direct	+0.08%	Acquired	(price as of 2026-08-20)
Oct. 1, 2015	MTX	A	464	—	—	4,874 Direct	+10.52%	Acquired	(price as of 2026-08-20)
Sept. 10, 2015	MTX	A	4	—	—	4,409 Direct	+0.09%	Acquired	(price as of 2026-08-20)
July 1, 2015	MTX	A	330	—	—	4,405 Direct	+8.10%	Acquired	(price as of 2026-08-20)
June 10, 2015	MTX	A	3	—	—	4,075 Direct	+0.07%	Acquired	(price as of 2026-08-20)
May 13, 2015	MTX	A	1,177	—	—	4,072 Direct	+40.66%	Acquired	(price as of 2026-08-20)
April 1, 2015	MTX	A	307	—	—	2,895 Direct	+11.86%	Acquired	(price as of 2026-08-20)
March 11, 2015	MTX	A	2	—	—	2,588 Direct	+0.08%	Acquired	(price as of 2026-08-20)
Jan. 2, 2015	MTX	A	353	—	—	2,610 Direct	+15.64%	Acquired	(price as of 2026-08-20)
Dec. 11, 2014	MTX	A	2	—	—	2,257 Direct	+0.09%	Acquired	(price as of 2026-08-20)
Oct. 1, 2014	MTX	A	353	—	—	2,255 Direct	+18.56%	Acquired	(price as of 2026-08-20)
Sept. 11, 2014	MTX	A	2	—	—	1,903 Direct	+0.11%	Acquired	(price as of 2026-08-20)
July 1, 2014	MTX	A	310	—	—	1,901 Direct	+19.48%	Acquired	(price as of 2026-08-20)
June 11, 2014	MTX	A	1	—	—	1,591 Direct	+0.06%	Acquired	(price as of 2026-08-20)
May 14, 2014	MTX	A	1,276	—	—	1,590 Direct	+406.37%	Acquired	(price as of 2026-08-20)
April 1, 2014	MTX	A	314	—	—	314 Direct	—	Acquired	(price as of 2026-08-20)
March 19, 2014	MTX	P	400	$60.02	$24,008	400 Direct	—	Acquired	17.8% (price as of 2026-08-20)
Nov. 11, 2005	NOC	S	100	$55.54	$5,554	111,150 Direct	-0.09%	Disposed	1052.7% (price as of 2026-08-20)
Nov. 11, 2005	NOC	M	11,250	$52.48	$590,400	111,250 Direct	+11.25%	Acquired	1119.9% (price as of 2026-08-20)
Nov. 11, 2005	NOC	M	10,000	$47.11	$471,100	100,000 Direct	+11.11%	Acquired	1258.9% (price as of 2026-08-20)
Nov. 11, 2005	NOC	M	11,250	$52.48	$590,400	33,750 Direct	-25.00%	Disposed	1119.9% (price as of 2026-08-20)
Nov. 11, 2005	NOC	M	10,000	$47.11	$471,100	20,000 Direct	-33.33%	Disposed	1258.9% (price as of 2026-08-20)
Nov. 11, 2005	NOC	S	14,550	$55.51	$807,670	90,000 Direct	-13.92%	Disposed	1053.3% (price as of 2026-08-20)
Nov. 11, 2005	NOC	S	6,600	$55.50	$366,300	104,550 Direct	-5.94%	Disposed	1053.5% (price as of 2026-08-20)
Nov. 7, 2005	NOC	S	14,474	$55.20	$798,965	90,000 Direct	-13.85%	Disposed	1059.8% (price as of 2026-08-20)
Aug. 5, 2005	NOC	M	15,000	$47.18	$707,700	15,000 Direct	-50.00%	Disposed	1256.9% (price as of 2026-08-20)
Aug. 5, 2005	NOC	M	10,000	$47.11	$471,100	30,000 Direct	-25.00%	Disposed	1258.9% (price as of 2026-08-20)
Aug. 5, 2005	NOC	S	2,700	$55.59	$150,093	104,474 Direct	-2.52%	Disposed	1051.6% (price as of 2026-08-20)
Aug. 5, 2005	NOC	S	8,300	$55.58	$461,314	107,174 Direct	-7.19%	Disposed	1051.8% (price as of 2026-08-20)
Aug. 5, 2005	NOC	S	1,000	$55.57	$55,570	115,474 Direct	-0.86%	Disposed	1052.0% (price as of 2026-08-20)
Aug. 5, 2005	NOC	S	9,000	$55.56	$500,040	116,474 Direct	-7.17%	Disposed	1052.2% (price as of 2026-08-20)
Aug. 5, 2005	NOC	S	4,000	$55.53	$222,120	125,474 Direct	-3.09%	Disposed	1052.9% (price as of 2026-08-20)
Aug. 5, 2005	NOC	M	15,000	$47.18	$707,700	129,474 Direct	+13.10%	Acquired	1256.9% (price as of 2026-08-20)
Aug. 5, 2005	NOC	M	10,000	$47.11	$471,100	114,474 Direct	+9.57%	Acquired	1258.9% (price as of 2026-08-20)
May 31, 2005	NOC	M	13,930	$46.79	$651,785	0 Direct	-100.00%	Disposed	1268.2% (price as of 2026-08-20)
May 31, 2005	NOC	M	16,072	$46.67	$750,080	0 Direct	-100.00%	Disposed	1271.7% (price as of 2026-08-20)
May 31, 2005	NOC	M	16,072	$49.85	$801,189	0 Direct	-100.00%	Disposed	1184.2% (price as of 2026-08-20)
May 31, 2005	NOC	S	130	$55.69	$7,240	104,474 Direct	-0.12%	Disposed	1049.6% (price as of 2026-08-20)
May 31, 2005	NOC	S	8,200	$55.63	$456,166	104,604 Direct	-7.27%	Disposed	1050.8% (price as of 2026-08-20)
May 31, 2005	NOC	S	5,600	$55.61	$311,416	112,804 Direct	-4.73%	Disposed	1051.2% (price as of 2026-08-20)
May 31, 2005	NOC	S	1,672	$55.60	$92,963	118,404 Direct	-1.39%	Disposed	1051.4% (price as of 2026-08-20)
May 31, 2005	NOC	S	128	$55.57	$7,113	120,076 Direct	-0.11%	Disposed	1052.0% (price as of 2026-08-20)
May 31, 2005	NOC	S	100	$55.53	$5,553	120,204 Direct	-0.08%	Disposed	1052.9% (price as of 2026-08-20)
May 31, 2005	NOC	S	8,400	$55.52	$466,368	120,304 Direct	-6.53%	Disposed	1053.1% (price as of 2026-08-20)
May 31, 2005	NOC	S	21,844	$55.44	$1,211,031	128,704 Direct	-14.51%	Disposed	1054.7% (price as of 2026-08-20)
May 31, 2005	NOC	M	13,930	$46.79	$651,785	150,548 Direct	+10.20%	Acquired	1268.2% (price as of 2026-08-20)
May 31, 2005	NOC	M	16,072	$46.67	$750,080	136,618 Direct	+13.33%	Acquired	1271.7% (price as of 2026-08-20)
May 31, 2005	NOC	M	16,072	$49.85	$801,189	120,546 Direct	+15.38%	Acquired	1184.2% (price as of 2026-08-20)
May 4, 2005	NOC	I	3,728	$55.50	$206,904	0 Indirect	-100.00%	Disposed	1053.5% (price as of 2026-08-20)
Feb. 28, 2005	NOC	A	24,000	$52.90	$1,269,600	104,474 Direct	+29.82%	Acquired	1110.2% (price as of 2026-08-20)
Nov. 3, 2004	NOC	M	74,998	$39.90	$2,992,420	74,998 Direct	—	Acquired	1504.5% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	400	$53.76	$21,504	74,598 Direct	-0.53%	Disposed	1090.8% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	1,100	$53.77	$59,147	73,498 Direct	-1.47%	Disposed	1090.6% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	1,000	$53.78	$53,780	72,498 Direct	-1.36%	Disposed	1090.4% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	500	$53.79	$26,895	71,998 Direct	-0.69%	Disposed	1090.2% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	71,698	$53.80	$3,857,352	300 Direct	-99.58%	Disposed	1089.9% (price as of 2026-08-20)
Nov. 3, 2004	NOC	S	300	$53.81	$16,143	0 Direct	-100.00%	Disposed	1089.7% (price as of 2026-08-20)
Nov. 3, 2004	NOC	M	74,998	$39.90	$2,992,420	0 Direct	-100.00%	Disposed	1504.5% (price as of 2026-08-20)
Aug. 30, 2004	NOC	M	48,214	$34.54	$1,665,312	0 Direct	-100.00%	Disposed	1753.5% (price as of 2026-08-20)
Aug. 30, 2004	NOC	S	48,214	$51.76	$2,495,557	0 Direct	-100.00%	Disposed	1136.8% (price as of 2026-08-20)
Aug. 30, 2004	NOC	M	48,214	$34.54	$1,665,312	48,214 Direct	—	Acquired	1753.5% (price as of 2026-08-20)
June 14, 2004	NOC	A	22,500	$104.97	$2,361,825	22,500 Direct	—	Acquired	1119.8% (price as of 2026-08-20)
Feb. 20, 2004	NOC	J	4,625	$104.17	$481,786	1,826 Indirect	-71.69%	Disposed	1129.1% (price as of 2026-08-20)
Feb. 20, 2004	NOC	J	4,625	$104.17	$481,786	1,826 Indirect	-71.69%	Disposed	1129.1% (price as of 2026-08-20)
Feb. 17, 2004	NOC	A	15,000	$104.21	$1,563,150	40,237 Direct	+59.44%	Acquired	1128.7% (price as of 2026-08-20)
Feb. 17, 2004	NOC	A	15,000	$104.21	$1,563,150	31,237 Direct	+92.38%	Acquired	1128.7% (price as of 2026-08-20)
Aug. 20, 2003	NOC	A	20,000	$94.22	$1,884,400	20,000 Direct	—	Acquired	1258.9% (price as of 2026-08-20)
Aug. 20, 2003	NOC	A	10,000	$94.22	$942,200	25,237 Direct	+65.63%	Acquired	1258.9% (price as of 2026-08-20)
Aug. 20, 2003	NOC	A	20,000	$94.22	$1,884,400	20,000 Direct	—	Acquired	1258.9% (price as of 2026-08-20)
Aug. 20, 2003	NOC	A	10,000	$94.22	$942,200	16,237 Direct	+160.33%	Acquired	1258.9% (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
July 2, 2018	MTX	Phantom Stock Units	Common Stock (297)	—	—	297	Acquired
June 14, 2018	MTX	Phantom Stock Units	Common Stock (8)	—	—	8	Acquired
May 16, 2018	MTX	Phantom Stock Units	Common Stock	—	—	1,381	Acquired
May 16, 2018	MTX	Phantom Stock Units	Common Stock (1,344)	—	—	1,344	Acquired
April 2, 2018	MTX	Phantom Stock Units	Common Stock (346)	—	—	346	Acquired
March 8, 2018	MTX	Phantom Stock Units	Common Stock (8)	—	—	8	Acquired
Jan. 2, 2018	MTX	Phantom Stock Units	Common Stock (324)	—	—	324	Acquired
Dec. 8, 2017	MTX	Phantom Stock Units	Common Stock (8)	—	—	8	Acquired
Oct. 2, 2017	MTX	Phantom Stock Units	Common Stock (310)	—	—	310	Acquired
Sept. 7, 2017	MTX	Phantom Stock Units	Common Stock (8)	—	—	8	Acquired
July 3, 2017	MTX	Phantom Stock Units	Common Stock (305)	—	—	305	Acquired
June 9, 2017	MTX	Phantom Stock Units	Common Stock (7)	—	—	7	Acquired
May 17, 2017	MTX	Phantom Stock Units	Common Stock (1,381)	—	—	1,381	Acquired
April 3, 2017	MTX	Phantom Stock Units	Common Stock (298)	—	—	298	Acquired
March 9, 2017	MTX	Phantom Stock Units	Common Stock (6)	—	—	6	Acquired
Jan. 3, 2017	MTX	Phantom Stock Units	Common Stock (289)	—	—	289	Acquired
Dec. 9, 2016	MTX	Phantom Stock Units	Common Stock (5)	—	—	5	Acquired
Dec. 9, 2016	MTX	Phantom Stock Units	Common Stock (5)	—	—	5	Acquired
Oct. 3, 2016	MTX	Phantom Stock Units	Common Stock (323)	—	—	323	Acquired
Sept. 8, 2016	MTX	Phantom Stock Units	Common Stock (6)	—	—	6	Acquired
July 1, 2016	MTX	Phantom Stock Units	Common Stock (392)	—	—	392	Acquired
June 9, 2016	MTX	Phantom Stock Units	Common Stock (6)	—	—	6	Acquired
May 11, 2016	MTX	Phantom Stock Units	Common Stock (1,496)	—	—	1,496	Acquired
April 1, 2016	MTX	Phantom Stock Units	Common Stock (394)	—	—	394	Acquired
March 10, 2016	MTX	Phantom Stock Units	Common Stock (5)	—	—	5	Acquired
Jan. 4, 2016	MTX	Phantom Stock Units	Common Stock (518)	—	—	518	Acquired
Dec. 10, 2015	MTX	Phantom Stock Units	Common Stock (4)	—	—	4	Acquired
Oct. 1, 2015	MTX	Phantom Stock Units	Common Stock (464)	—	—	464	Acquired
Sept. 10, 2015	MTX	Phantom Stock Units	Common Stock (4)	—	—	4	Acquired
July 1, 2015	MTX	Phantom Stock Units	Common Stock (330)	—	—	330	Acquired
June 10, 2015	MTX	Phantom Stock Units	Common Stock (3)	—	—	3	Acquired
May 13, 2015	MTX	Phantom Stock Units	Common Stock (1,177)	—	—	1,177	Acquired
April 1, 2015	MTX	Phantom Stock Units	Common Stock (307)	—	—	307	Acquired
March 11, 2015	MTX	Phantom Stock Units	Common Stock (2)	—	—	2	Acquired
Jan. 2, 2015	MTX	Phantom Stock Units	Common Stock (353)	—	—	353	Acquired
Dec. 11, 2014	MTX	Phantom Stock Units	Common Stock (2)	—	—	2	Acquired
Oct. 1, 2014	MTX	Phantom Stock Units	Common Stock (353)	—	—	353	Acquired
Sept. 11, 2014	MTX	Phantom Stock Units	Common Stock (2)	—	—	2	Acquired
July 1, 2014	MTX	Phantom Stock Units	Common Stock (310)	—	—	310	Acquired
June 11, 2014	MTX	Phantom Stock Units	Common Stock (1)	—	—	1	Acquired
May 14, 2014	MTX	Phantom Stock Units	Common Stock (1,276)	—	—	1,276	Acquired
April 1, 2014	MTX	Phantom Stock Units	Common Stock (314)	—	—	314	Acquired
Nov. 11, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (11,250)	$52.48	June 14, 2014	11,250	Disposed
Nov. 11, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (10,000)	$47.11	Aug. 20, 2013	10,000	Disposed
Aug. 5, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (15,000)	$47.18	Dec. 18, 2012	15,000	Disposed
Aug. 5, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (10,000)	$47.11	Aug. 20, 2013	10,000	Disposed
May 31, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (13,930)	$46.79	Feb. 4, 2007	13,930	Disposed
May 31, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (16,027)	$46.67	Feb. 10, 2009	16,072	Disposed
May 31, 2005	NOC	Stock Option (Right-to-Buy)	Common Stock (16,072)	$49.85	Feb. 11, 2008	16,072	Disposed
Nov. 3, 2004	NOC	Stock Option (right-to-buy)	Common Stock (74,998)	$39.90	Feb. 15, 2010	74,998	Disposed
Aug. 30, 2004	NOC	Stock Option (right-to-buy)	Common Stock (48,214)	$34.54	Feb. 20, 2012	48,214	Disposed
June 14, 2004	NOC	Stock Option (Right-to-Buy)	Common Stock	—	June 14, 2014	22,500	Acquired
Aug. 20, 2003	NOC	Stock Option (Right-to-Buy)	Common Stock (20,000)	$94.22	Aug. 19, 2013	20,000	Acquired
Aug. 20, 2003	NOC	Stock Option (Right-to-Buy)	Common Stock (20,000)	$94.22	Aug. 19, 2013	20,000	Acquired

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

Initial ownership (Form 3) 2 holdings

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

Date	Ticker	Security	Shares	Ownership
Sept. 11, 2015	MTX	Common Stock	0	Direct
Feb. 4, 2014	MTX	Common Stock	0	Direct