Dj Monagle III

Insider

First SEC filing: Jan. 10, 2008 · Latest: Jan. 27, 2026

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

MTX selling Dec. 29, 2025

Insider transactions

0 buys (P) 1 sells (S) Net: $-1,429,457 + 96 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

96 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
Jan. 26, 2026	MTX	M	3,519	—	—	23,282 Direct	-13.13%	Disposed	(price as of 2026-08-20)
Jan. 26, 2026	MTX	F	1,947	$68.89	$134,129	89,073 Direct	-2.14%	Disposed	2.6% (price as of 2026-08-20)
Jan. 26, 2026	MTX	M	3,519	—	—	91,020 Direct	+4.02%	Acquired	(price as of 2026-08-20)
Jan. 23, 2026	MTX	M	3,795	—	—	26,801 Direct	-12.40%	Disposed	(price as of 2026-08-20)
Jan. 23, 2026	MTX	F	2,099	$68.77	$144,348	87,501 Direct	-2.34%	Disposed	2.8% (price as of 2026-08-20)
Jan. 23, 2026	MTX	M	3,795	—	—	89,600 Direct	+4.42%	Acquired	(price as of 2026-08-20)
Jan. 21, 2026	MTX	M	3,492	—	—	30,596 Direct	-10.24%	Disposed	(price as of 2026-08-20)
Jan. 21, 2026	MTX	F	2,036	$66.92	$136,249	85,805 Direct	-2.32%	Disposed	5.6% (price as of 2026-08-20)
Jan. 21, 2026	MTX	M	3,492	—	—	87,841 Direct	+4.14%	Acquired	(price as of 2026-08-20)
Jan. 20, 2026	MTX	A	10,739	—	—	10,739 Direct	—	Acquired	(price as of 2026-08-20)
Jan. 20, 2026	MTX	A	12,504	—	—	34,088 Direct	+57.93%	Acquired	(price as of 2026-08-20)
Dec. 29, 2025	MTX	M	23,093	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Dec. 29, 2025	MTX	S	23,093	$61.90	$1,429,457	84,349 Direct	-21.49%	Disposed	14.2% (price as of 2026-08-20)
Dec. 29, 2025	MTX	M	23,093	$38.28	$884,000	107,442 Direct	+27.38%	Acquired	84.6% (price as of 2026-08-20)
June 5, 2024	MTX	I	4,224	$85.62	$361,659	0 Direct	-100.00%	Disposed	-17.4% (price as of 2026-08-20)
April 1, 2015	MTX	M	103	—	—	22,597 Direct	-0.45%	Disposed	(price as of 2026-08-20)
April 1, 2015	MTX	F	48	$72.53	$3,481	46,626 Direct	-0.10%	Disposed	-2.6% (price as of 2026-08-20)
April 1, 2015	MTX	M	103	—	—	46,674 Direct	+0.22%	Acquired	(price as of 2026-08-20)
Jan. 25, 2015	MTX	M	4,110	—	—	22,700 Direct	-15.33%	Disposed	(price as of 2026-08-20)
Jan. 25, 2015	MTX	F	1,300	$61.43	$79,859	46,571 Direct	-2.72%	Disposed	15.1% (price as of 2026-08-20)
Jan. 25, 2015	MTX	M	4,110	—	—	47,871 Direct	+9.39%	Acquired	(price as of 2026-08-20)
Jan. 22, 2015	MTX	M	2,531	—	—	26,810 Direct	-8.63%	Disposed	(price as of 2026-08-20)
Jan. 22, 2015	MTX	M	3,423	—	—	29,341 Direct	-10.45%	Disposed	(price as of 2026-08-20)
Jan. 22, 2015	MTX	F	801	$61.06	$48,909	43,761 Direct	-1.80%	Disposed	15.8% (price as of 2026-08-20)
Jan. 22, 2015	MTX	M	2,531	—	—	44,562 Direct	+6.02%	Acquired	(price as of 2026-08-20)
Jan. 22, 2015	MTX	F	1,144	$61.06	$69,853	42,031 Direct	-2.65%	Disposed	15.8% (price as of 2026-08-20)
Jan. 22, 2015	MTX	M	3,423	—	—	43,175 Direct	+8.61%	Acquired	(price as of 2026-08-20)
Jan. 20, 2015	MTX	A	13,911	—	—	32,764 Direct	+73.79%	Acquired	(price as of 2026-08-20)
Jan. 20, 2015	MTX	A	14,229	—	—	141,822 Direct	+11.15%	Acquired	(price as of 2026-08-20)
Dec. 26, 2014	MTX	F	605	$71.25	$43,106	39,752 Direct	-1.50%	Disposed	-0.8% (price as of 2026-08-20)
Dec. 23, 2014	MTX	M	2,200	—	—	127,593 Direct	-1.70%	Disposed	(price as of 2026-08-20)
Dec. 23, 2014	MTX	M	2,000	—	—	129,793 Direct	-1.52%	Disposed	(price as of 2026-08-20)
Dec. 23, 2014	MTX	M	2,501	$71.73	$179,397	40,357 Direct	+6.61%	Acquired	-1.5% (price as of 2026-08-20)
April 1, 2014	MTX	A	307	—	—	18,853 Direct	+1.66%	Acquired	(price as of 2026-08-20)
April 1, 2014	MTX	A	1,180	—	—	129,793 Direct	+0.92%	Acquired	(price as of 2026-08-20)
Jan. 27, 2014	MTX	M	3,764	—	—	19,822 Direct	-15.96%	Disposed	(price as of 2026-08-20)
Jan. 27, 2014	MTX	M	4,110	—	—	22,986 Direct	-15.17%	Disposed	(price as of 2026-08-20)
Jan. 27, 2014	MTX	F	1,190	$56.00	$66,640	37,856 Direct	-3.05%	Disposed	26.2% (price as of 2026-08-20)
Jan. 27, 2014	MTX	M	3,764	—	—	39,046 Direct	+10.67%	Acquired	(price as of 2026-08-20)
Jan. 27, 2014	MTX	M	4,110	—	—	36,582 Direct	+12.66%	Acquired	(price as of 2026-08-20)
Jan. 22, 2014	MTX	F	1,300	$56.00	$72,800	35,282 Direct	-3.55%	Disposed	26.2% (price as of 2026-08-20)
Jan. 22, 2014	MTX	A	7,591	—	—	26,420 Direct	+40.32%	Acquired	(price as of 2026-08-20)
Jan. 22, 2014	MTX	A	14,958	—	—	128,973 Direct	+13.12%	Acquired	(price as of 2026-08-20)
Jan. 22, 2014	MTX	M	3,423	—	—	18,829 Direct	-15.38%	Disposed	(price as of 2026-08-20)
Jan. 22, 2014	MTX	F	1,149	$57.97	$66,608	32,472 Direct	-3.42%	Disposed	21.9% (price as of 2026-08-20)
Jan. 22, 2014	MTX	M	3,423	—	—	33,621 Direct	+11.34%	Acquired	(price as of 2026-08-20)
Dec. 5, 2013	MTX	M	1,500	—	—	116,015 Direct	-1.28%	Disposed	(price as of 2026-08-20)
Dec. 5, 2013	MTX	M	804	$58.09	$46,704	30,198 Direct	+2.74%	Acquired	21.7% (price as of 2026-08-20)
Jan. 28, 2013	MTX	M	3,764	—	—	28,261 Direct	+15.37%	Acquired	(price as of 2026-08-20)
Jan. 28, 2013	MTX	F	1,303	$41.80	$54,465	26,958 Direct	-4.61%	Disposed	69.1% (price as of 2026-08-20)
Jan. 28, 2013	MTX	M	3,726	—	—	30,684 Direct	+13.82%	Acquired	(price as of 2026-08-20)
Jan. 28, 2013	MTX	F	1,290	$41.80	$53,922	29,394 Direct	-4.20%	Disposed	69.1% (price as of 2026-08-20)
Jan. 28, 2013	MTX	M	3,764	—	—	25,978 Direct	-12.66%	Disposed	(price as of 2026-08-20)
Jan. 28, 2013	MTX	M	3,726	—	—	22,252 Direct	-14.34%	Disposed	(price as of 2026-08-20)
Jan. 25, 2013	MTX	M	4,112	—	—	29,742 Direct	-12.15%	Disposed	(price as of 2026-08-20)
Jan. 25, 2013	MTX	F	1,513	$41.62	$62,971	24,497 Direct	-5.82%	Disposed	69.8% (price as of 2026-08-20)
Jan. 25, 2013	MTX	M	4,112	—	—	26,010 Direct	+18.78%	Acquired	(price as of 2026-08-20)
Jan. 22, 2013	MTX	A	10,268	—	—	33,854 Direct	+43.53%	Acquired	(price as of 2026-08-20)
Jan. 22, 2013	MTX	A	19,673	—	—	117,515 Direct	+20.11%	Acquired	(price as of 2026-08-20)
Jan. 28, 2012	MTX	M	2,533	—	—	11,793 Direct	-17.68%	Disposed	(price as of 2026-08-20)
Jan. 28, 2012	MTX	F	779	$63.95	$49,817	10,949 Direct	-6.64%	Disposed	121.0% (price as of 2026-08-20)
Jan. 28, 2012	MTX	M	2,533	—	—	11,728 Direct	+27.55%	Acquired	(price as of 2026-08-20)
Jan. 27, 2012	MTX	M	1,863	—	—	14,326 Direct	-11.51%	Disposed	(price as of 2026-08-20)
Jan. 27, 2012	MTX	F	571	$64.61	$36,892	9,195 Direct	-5.85%	Disposed	118.8% (price as of 2026-08-20)
Jan. 27, 2012	MTX	M	1,863	—	—	9,766 Direct	+23.57%	Acquired	(price as of 2026-08-20)
Jan. 26, 2012	MTX	P	0	—	—	704 Indirect	0.00%	Acquired	(price as of 2026-08-20)
Jan. 26, 2012	MTX	P	0	—	—	704 Indirect	0.00%	Acquired	(price as of 2026-08-20)
Jan. 26, 2012	MTX	M	1,883	—	—	16,189 Direct	-10.42%	Disposed	(price as of 2026-08-20)
Jan. 26, 2012	MTX	P	0	—	—	704 Indirect	0.00%	Acquired	(price as of 2026-08-20)
Jan. 26, 2012	MTX	F	631	$64.36	$40,611	7,903 Direct	-7.39%	Disposed	119.6% (price as of 2026-08-20)
Jan. 26, 2012	MTX	M	1,883	—	—	8,534 Direct	+28.31%	Acquired	(price as of 2026-08-20)
Jan. 25, 2012	MTX	A	6,166	—	—	18,072 Direct	+51.79%	Acquired	(price as of 2026-08-20)
Jan. 25, 2012	MTX	A	10,239	—	—	48,921 Direct	+26.47%	Acquired	(price as of 2026-08-20)
Feb. 27, 2011	MTX	M	500	—	—	6,804 Direct	+7.93%	Acquired	(price as of 2026-08-20)
Feb. 27, 2011	MTX	F	153	$64.32	$9,841	6,651 Direct	-2.25%	Disposed	119.8% (price as of 2026-08-20)
Feb. 27, 2011	MTX	M	500	—	—	11,440 Direct	-4.19%	Disposed	(price as of 2026-08-20)
Jan. 28, 2011	MTX	M	2,533	—	—	7,080 Direct	+55.71%	Acquired	(price as of 2026-08-20)
Jan. 28, 2011	MTX	F	776	$63.42	$49,214	6,304 Direct	-10.96%	Disposed	122.9% (price as of 2026-08-20)
Jan. 28, 2011	MTX	M	2,533	—	—	11,940 Direct	-17.50%	Disposed	(price as of 2026-08-20)
Jan. 27, 2011	MTX	M	1,864	—	—	5,171 Direct	+56.37%	Acquired	(price as of 2026-08-20)
Jan. 27, 2011	MTX	F	624	$64.45	$40,217	4,547 Direct	-12.07%	Disposed	119.3% (price as of 2026-08-20)
Jan. 27, 2011	MTX	M	1,864	—	—	14,473 Direct	-11.41%	Disposed	(price as of 2026-08-20)
Jan. 26, 2011	MTX	A	5,647	—	—	16,337 Direct	+52.83%	Acquired	(price as of 2026-08-20)
Jan. 26, 2011	MTX	A	9,182	—	—	35,832 Direct	+34.45%	Acquired	(price as of 2026-08-20)
April 26, 2010	MTX	M	233	—	—	10,690 Direct	-2.13%	Disposed	(price as of 2026-08-20)
April 26, 2010	MTX	F	71	$59.12	$4,198	3,307 Direct	-2.10%	Disposed	139.1% (price as of 2026-08-20)
April 26, 2010	MTX	M	233	—	—	3,378 Direct	+7.41%	Acquired	(price as of 2026-08-20)
March 1, 2010	MTX	M	500	—	—	10,923 Direct	-4.38%	Disposed	(price as of 2026-08-20)
March 1, 2010	MTX	F	153	$49.40	$7,558	3,145 Direct	-4.64%	Disposed	186.2% (price as of 2026-08-20)
March 1, 2010	MTX	M	500	—	—	3,298 Direct	+17.87%	Acquired	(price as of 2026-08-20)
Jan. 28, 2010	MTX	M	2,534	—	—	5,833 Direct	-30.29%	Disposed	(price as of 2026-08-20)
Jan. 28, 2010	MTX	F	882	$48.27	$42,574	2,798 Direct	-23.97%	Disposed	192.9% (price as of 2026-08-20)
Jan. 28, 2010	MTX	M	2,534	—	—	3,680 Direct	+221.12%	Acquired	(price as of 2026-08-20)
Jan. 27, 2010	MTX	A	9,550	—	—	26,650 Direct	+55.85%	Acquired	(price as of 2026-08-20)
Jan. 27, 2010	MTX	A	5,590	—	—	11,423 Direct	+95.83%	Acquired	(price as of 2026-08-20)
April 27, 2009	MTX	M	233	—	—	767 Direct	-23.30%	Disposed	(price as of 2026-08-20)
April 27, 2009	MTX	M	233	—	—	1,000 Direct	-18.90%	Disposed	(price as of 2026-08-20)
April 27, 2009	MTX	F	71	$36.49	$2,591	1,146 Direct	-5.83%	Disposed	287.4% (price as of 2026-08-20)
Jan. 28, 2009	MTX	A	7,600	—	—	8,367 Direct	+990.87%	Acquired	(price as of 2026-08-20)
Jan. 28, 2009	MTX	A	12,000	—	—	17,100 Direct	+235.29%	Acquired	(price as of 2026-08-20)

Showing latest 100 of 116 transactions

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. 26, 2026	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,519)	—	—	3,519	Disposed
Jan. 23, 2026	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,795)	—	—	3,795	Disposed
Jan. 21, 2026	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,492)	—	—	3,492	Disposed
Jan. 20, 2026	MTX	Employee Stock Option (Right to Buy)	Common Stock (10,739)	$66.23	Jan. 20, 2036	10,739	Acquired
Jan. 20, 2026	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (12,504)	—	—	12,504	Acquired
Dec. 29, 2025	MTX	EMPLOYEE Stock Option (Right to Buy)	Common Stock (23,093)	$38.28	Jan. 19, 2026	23,093	Disposed
June 5, 2024	MTX	PHANTOM STOCK UNITS	COMMON STOCK (4,224)	—	—	4,224	Disposed
April 1, 2015	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (103)	—	—	103	Disposed
Jan. 25, 2015	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (4,110)	—	—	4,110	Disposed
Jan. 22, 2015	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (2,531)	—	—	2,531	Disposed
Jan. 22, 2015	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,423)	—	—	3,423	Disposed
Jan. 20, 2015	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (13,911)	—	—	13,911	Acquired
Jan. 20, 2015	MTX	Employee Stock Option (Right to Buy)	Common Stock (14,229)	$60.18	Jan. 20, 2025	14,229	Acquired
Dec. 23, 2014	MTX	Employee Stock Option (Right to Buy)	Common Stock (2,200)	$29.66	April 26, 2016	2,200	Disposed
Dec. 23, 2014	MTX	Employee Stock Option (Right to Buy)	Common Stock (2,000)	$28.26	Jan. 17, 2016	2,000	Disposed
April 1, 2014	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (307)	—	—	307	Acquired
April 1, 2014	MTX	Employee Stock Option (Right to Buy)	Common Stock (1,180)	$65.16	April 1, 2024	1,180	Acquired
Jan. 27, 2014	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,764)	—	—	3,764	Disposed
Jan. 27, 2014	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (4,110)	—	—	4,110	Disposed
Jan. 22, 2014	MTX	Deferred Restricted Stock Units ("DRSUs")	Common Stock (7,591)	—	—	7,591	Acquired
Jan. 22, 2014	MTX	Employee Stock Option (Right to Buy)	Common Stock (14,958)	$57.96	Jan. 22, 2024	14,958	Acquired
Jan. 22, 2014	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,423)	—	—	3,423	Disposed
Dec. 5, 2013	MTX	Employee Stock Option (Right to Buy)	Common Stock (1,500)	$26.94	Feb. 25, 2014	1,500	Disposed
Jan. 28, 2013	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (3,764)	—	—	3,764	Disposed
Jan. 28, 2013	MTX	DRSUs	Common Stock (3,726)	—	—	3,726	Disposed
Jan. 25, 2013	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (4,112)	—	—	4,112	Disposed
Jan. 22, 2013	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (10,268)	—	—	10,268	Acquired
Jan. 22, 2013	MTX	Employee Stock Option (Right to Buy)	Common Stock (19,673)	$41.29	Jan. 22, 2023	19,673	Acquired
Jan. 28, 2012	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (2,533)	—	—	2,533	Disposed
Jan. 27, 2012	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (1,863)	—	—	1,863	Disposed
Jan. 26, 2012	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (1,883)	—	—	1,883	Disposed
Jan. 25, 2012	MTX	Deferred Restricted Stock Units (DRSUs)	Commons Stock (6,166)	—	—	6,166	Acquired
Jan. 25, 2012	MTX	Employee Stock Option (Right to Buy)	Common Stock (10,239)	$64.06	Jan. 25, 2022	10,239	Acquired
Feb. 27, 2011	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (500)	—	—	500	Disposed
Jan. 28, 2011	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (2,533)	—	—	2,533	Disposed
Jan. 27, 2011	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (1,864)	—	—	1,864	Disposed
Jan. 26, 2011	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (5,647)	—	—	5,647	Acquired
Jan. 26, 2011	MTX	Employee Stock Option (Right to Buy)	Common Stock (9,182)	$64.46	Jan. 26, 2021	9,182	Acquired
April 26, 2010	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (233)	—	—	233	Disposed
March 1, 2010	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (500)	—	—	500	Disposed
Jan. 28, 2010	MTX	DRSUs	Common Stock (2,534)	—	—	2,534	Disposed
Jan. 27, 2010	MTX	Employee Stock Option (Right to Buy)	Common Stock (9,550)	$49.12	Jan. 27, 2020	9,550	Acquired
Jan. 27, 2010	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (5,590)	—	—	5,590	Acquired
April 27, 2009	MTX	DRSUs	Common Stock (233)	—	—	233	Disposed
April 27, 2009	MTX	Deferred Restricted Stock Units ("DRSUs")	Common Stock (233)	—	—	233	Disposed
Feb. 27, 2009	MTX	Deferred Restricted Stock Units ("DRSUs")	Common Stock (500)	—	—	500	Disposed
Jan. 28, 2009	MTX	Deferred Restricted Stock Units (DRSUs)	Common Stock (7,600)	—	—	7,600	Acquired
Jan. 28, 2009	MTX	Employee Stock Option (Right to Buy)	Common Stock (12,000)	$39.71	Jan. 28, 2019	12,000	Acquired
April 28, 2008	MTX	DRSUs	Common Stock (233)	—	—	233	Disposed
April 25, 2008	MTX	Deferred Restricted Stock Units ("DRSUs")	Common Stock (234)	—	—	234	Disposed
Feb. 27, 2008	MTX	Deferred Restricted Stock Units ("DRSUs")	Common Stock (1,500)	—	—	1,500	Acquired
Feb. 27, 2008	MTX	Employee Stock Option (Right to Buy)	Common Stock (4,000)	$64.16	Feb. 27, 2018	4,000	Acquired

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

Initial ownership (Form 3) 8 holdings

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

Date	Ticker	Security	Shares	Ownership
Jan. 10, 2008	MTX	Common Stock	149	Direct
Jan. 10, 2008	MTX	Common Stock	49	Indirect
Jan. 10, 2008	MTX	Employee Stock Option (Right to Buy)→ Common Stock (750)	750	Direct
Jan. 10, 2008	MTX	Employee Stock Option (Right to Buy)→ Common Stock (1,000)	1,000	Direct
Jan. 10, 2008	MTX	Employee Stock Option (Right to Buy)→ Common Stock (1,100)	1,100	Direct
Jan. 10, 2008	MTX	Employee Stock Option (Right to Buy)→ Common Stock (1,100)	1,100	Direct
Jan. 10, 2008	MTX	Deffered Restricted Stock Units ("DRSUs")→ Common Stock (466)	466	Direct
Jan. 10, 2008	MTX	DRSUs→ Common Stock (700)	700	Direct

Compensation (DEF 14A)

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

MTX

III Group President, Consumer & Specialties

Fiscal year	Salary	Bonus	Stock awards	Option awards	Non-equity incentive	Pension change	Other	Total
2023	$642,081	—	$697,554	$455,347	$1,107,921	$189,696	$18,200	$3,110,799
2022	$612,289	—	$664,312	$396,536	$931,167	$128,884	$17,200	$2,750,389
2021	$589,464	—	$626,934	$313,460	$1,081,721	$15,994	$38,412	$2,665,985

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