Steven C. Marshall

Insider

First SEC filing: Nov. 1, 2018 · Latest: Nov. 1, 2018

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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.
Compensation Executive pay disclosed in company proxy statements.

Insider at

AMT selling Oct. 30, 2018

Insider transactions

0 buys (P) 0 sells (S) Net: $0 + 86 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

86 other filings hidden

Date	Ticker	Code	Shares	Price	Value	Owned after	Δ own	A/D	vs now
Oct. 30, 2018	AMT	M	61,368	$50.78	$3,116,267	166,203 Direct	+58.54%	Acquired	249.1% (price as of 2026-08-20)
Oct. 30, 2018	AMT	S 10b5-1	61,368	$154.00	$9,450,672	104,835 Direct	-36.92%	Disposed	15.1% (price as of 2026-08-20)
Oct. 30, 2018	AMT	M	71,798	$62.00	$4,451,476	176,633 Direct	+68.49%	Acquired	186.0% (price as of 2026-08-20)
Oct. 30, 2018	AMT	S 10b5-1	71,798	$158.00	$11,344,084	104,835 Direct	-40.65%	Disposed	12.2% (price as of 2026-08-20)
Oct. 30, 2018	AMT	M	30,000	$43.11	$1,293,300	134,835 Direct	+28.62%	Acquired	311.3% (price as of 2026-08-20)
Oct. 30, 2018	AMT	S 10b5-1	30,000	$160.00	$4,800,000	104,835 Direct	-22.25%	Disposed	10.8% (price as of 2026-08-20)
Oct. 30, 2018	AMT	M	61,368	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Oct. 30, 2018	AMT	M	71,798	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
Oct. 30, 2018	AMT	M	30,000	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
March 12, 2018	AMT	A	11,856	—	—	104,694 Direct	+12.77%	Acquired	(price as of 2026-08-20)
March 10, 2018	AMT	F	13,118	$143.58	$1,883,482	92,838 Direct	-12.38%	Disposed	23.5% (price as of 2026-08-20)
Feb. 27, 2018	AMT	A	6,468	—	—	105,956 Direct	+6.50%	Acquired	(price as of 2026-08-20)
June 27, 2017	AMT	M	17,162	$28.39	$487,229	119,994 Direct	+16.69%	Acquired	524.5% (price as of 2026-08-20)
June 27, 2017	AMT	S 10b5-1	20,548	$134.92	$2,772,336	99,446 Direct	-17.12%	Disposed	31.4% (price as of 2026-08-20)
June 27, 2017	AMT	M	17,162	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
March 11, 2017	AMT	F	2,004	$113.58	$227,614	102,640 Direct	-1.92%	Disposed	56.1% (price as of 2026-08-20)
March 10, 2017	AMT	A	14,087	—	—	109,372 Direct	+14.78%	Acquired	(price as of 2026-08-20)
March 10, 2017	AMT	F	4,728	$113.58	$537,006	104,644 Direct	-4.32%	Disposed	56.1% (price as of 2026-08-20)
Feb. 27, 2017	AMT	A	5,539	—	—	95,285 Direct	+6.17%	Acquired	(price as of 2026-08-20)
July 12, 2016	AMT	M	50,000	$44.92	$2,246,000	139,689 Direct	+55.75%	Acquired	294.7% (price as of 2026-08-20)
July 12, 2016	AMT	S 10b5-1	25,000	$115.00	$2,875,000	114,689 Direct	-17.90%	Disposed	54.2% (price as of 2026-08-20)
July 12, 2016	AMT	S 10b5-1	25,000	$116.00	$2,900,000	89,689 Direct	-21.80%	Disposed	52.8% (price as of 2026-08-20)
July 12, 2016	AMT	M	50,000	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
July 11, 2016	AMT	M	50,000	$44.92	$2,246,000	139,689 Direct	+55.75%	Acquired	294.7% (price as of 2026-08-20)
July 11, 2016	AMT	S 10b5-1	25,000	$113.68	$2,842,000	114,689 Direct	-17.90%	Disposed	56.0% (price as of 2026-08-20)
July 11, 2016	AMT	S 10b5-1	25,000	$114.00	$2,850,000	89,689 Direct	-21.80%	Disposed	55.5% (price as of 2026-08-20)
July 11, 2016	AMT	M	50,000	—	—	50,000 Direct	-50.00%	Disposed	(price as of 2026-08-20)
July 8, 2016	AMT	M	50,000	$44.92	$2,246,000	139,689 Direct	+55.75%	Acquired	294.7% (price as of 2026-08-20)
July 8, 2016	AMT	S 10b5-1	50,000	$112.81	$5,640,500	89,689 Direct	-35.79%	Disposed	57.2% (price as of 2026-08-20)
July 8, 2016	AMT	M	50,000	—	—	100,000 Direct	-33.33%	Disposed	(price as of 2026-08-20)
March 12, 2016	AMT	F	2,231	$98.46	$219,664	89,501 Direct	-2.43%	Disposed	80.1% (price as of 2026-08-20)
March 11, 2016	AMT	F	2,036	$98.46	$200,465	91,732 Direct	-2.17%	Disposed	80.1% (price as of 2026-08-20)
March 10, 2016	AMT	A	15,500	—	—	96,709 Direct	+19.09%	Acquired	(price as of 2026-08-20)
March 10, 2016	AMT	F	2,941	$94.71	$278,542	93,768 Direct	-3.04%	Disposed	87.2% (price as of 2026-08-20)
Feb. 26, 2016	AMT	A	4,617	—	—	81,209 Direct	+6.03%	Acquired	(price as of 2026-08-20)
March 12, 2015	AMT	F	2,280	$96.27	$219,496	81,387 Direct	-2.73%	Disposed	84.2% (price as of 2026-08-20)
March 11, 2015	AMT	F	2,081	$94.63	$196,925	78,627 Direct	-2.58%	Disposed	87.4% (price as of 2026-08-20)
March 10, 2015	AMT	A	9,702	—	—	85,258 Direct	+12.84%	Acquired	(price as of 2026-08-20)
March 10, 2015	AMT	F	4,550	$94.57	$430,294	80,708 Direct	-5.34%	Disposed	87.5% (price as of 2026-08-20)
March 10, 2015	AMT	A	121,604	—	—	121,604 Direct	—	Acquired	(price as of 2026-08-20)
March 12, 2014	AMT	M	5,041	—	—	28,926 Direct	+21.11%	Acquired	(price as of 2026-08-20)
March 12, 2014	AMT	F	2,293	$80.84	$185,366	26,633 Direct	-7.93%	Disposed	119.3% (price as of 2026-08-20)
March 12, 2014	AMT	M	5,041	—	—	10,080 Direct	-33.34%	Disposed	(price as of 2026-08-20)
March 11, 2014	AMT	M	4,552	—	—	25,983 Direct	+21.24%	Acquired	(price as of 2026-08-20)
March 11, 2014	AMT	F	2,098	$81.70	$171,407	23,885 Direct	-8.07%	Disposed	117.0% (price as of 2026-08-20)
March 11, 2014	AMT	M	4,552	—	—	13,654 Direct	-25.00%	Disposed	(price as of 2026-08-20)
March 10, 2014	AMT	M	5,219	—	—	20,578 Direct	+33.98%	Acquired	(price as of 2026-08-20)
March 10, 2014	AMT	F	1,896	$81.18	$153,917	18,682 Direct	-9.21%	Disposed	118.4% (price as of 2026-08-20)
March 10, 2014	AMT	M	5,169	—	—	23,851 Direct	+27.67%	Acquired	(price as of 2026-08-20)
March 10, 2014	AMT	F	2,420	$81.18	$196,456	21,431 Direct	-10.15%	Disposed	118.4% (price as of 2026-08-20)
March 10, 2014	AMT	M	5,219	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
March 10, 2014	AMT	M	5,169	—	—	5,169 Direct	-50.00%	Disposed	(price as of 2026-08-20)
March 10, 2014	AMT	A	107,817	—	—	107,817 Direct	—	Acquired	(price as of 2026-08-20)
March 10, 2014	AMT	A	19,710	—	—	19,710 Direct	—	Acquired	(price as of 2026-08-20)
March 12, 2013	AMT	M	5,041	—	—	17,357 Direct	+40.93%	Acquired	(price as of 2026-08-20)
March 12, 2013	AMT	F	2,330	$76.03	$177,150	15,027 Direct	-13.42%	Disposed	133.2% (price as of 2026-08-20)
March 12, 2013	AMT	M	5,041	—	—	15,121 Direct	-25.00%	Disposed	(price as of 2026-08-20)
March 11, 2013	AMT	A	72,539	—	—	72,539 Direct	—	Acquired	(price as of 2026-08-20)
March 11, 2013	AMT	A	18,206	—	—	18,206 Direct	—	Acquired	(price as of 2026-08-20)
March 10, 2013	AMT	M	5,283	—	—	8,693 Direct	+154.93%	Acquired	(price as of 2026-08-20)
March 10, 2013	AMT	F	1,897	$77.14	$146,335	6,796 Direct	-21.82%	Disposed	129.8% (price as of 2026-08-20)
March 10, 2013	AMT	M	5,219	—	—	12,015 Direct	+76.80%	Acquired	(price as of 2026-08-20)
March 10, 2013	AMT	F	2,446	$77.14	$188,684	9,569 Direct	-20.36%	Disposed	129.8% (price as of 2026-08-20)
March 10, 2013	AMT	M	5,170	—	—	14,739 Direct	+54.03%	Acquired	(price as of 2026-08-20)
March 10, 2013	AMT	F	2,423	$77.14	$186,910	12,316 Direct	-16.44%	Disposed	129.8% (price as of 2026-08-20)
March 10, 2013	AMT	M	5,283	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
March 10, 2013	AMT	M	5,219	—	—	5,219 Direct	-50.00%	Disposed	(price as of 2026-08-20)
March 10, 2013	AMT	M	5,170	—	—	10,338 Direct	-33.34%	Disposed	(price as of 2026-08-20)
Aug. 1, 2012	AMT	M	30,000	$43.11	$1,293,300	33,410 Direct	+879.77%	Acquired	311.3% (price as of 2026-08-20)
Aug. 1, 2012	AMT	S 10b5-1	30,000	$74.00	$2,220,000	3,410 Direct	-89.79%	Disposed	139.6% (price as of 2026-08-20)
Aug. 1, 2012	AMT	M	30,000	—	—	30,000 Direct	-50.00%	Disposed	(price as of 2026-08-20)
July 10, 2012	AMT	M	32,500	$37.70	$1,225,250	35,910 Direct	+953.08%	Acquired	370.3% (price as of 2026-08-20)
July 10, 2012	AMT	S 10b5-1	32,500	$72.00	$2,340,000	3,410 Direct	-90.50%	Disposed	146.2% (price as of 2026-08-20)
July 10, 2012	AMT	M	32,500	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
June 29, 2012	AMT	M	51,488	$28.39	$1,461,744	54,898 Direct	+1509.91%	Acquired	524.5% (price as of 2026-08-20)
June 29, 2012	AMT	S 10b5-1	51,488	$70.13	$3,610,853	3,410 Direct	-93.79%	Disposed	152.8% (price as of 2026-08-20)
June 29, 2012	AMT	M	51,488	—	—	17,162 Direct	-75.00%	Disposed	(price as of 2026-08-20)
June 19, 2012	AMT	S 10b5-1	14,272	$69.00	$984,768	3,410 Direct	-80.71%	Disposed	156.9% (price as of 2026-08-20)
June 14, 2012	AMT	S 10b5-1	7,564	$67.00	$506,788	17,682 Direct	-29.96%	Disposed	164.6% (price as of 2026-08-20)
March 17, 2012	AMT	M	2,322	—	—	25,800 Direct	+9.89%	Acquired	(price as of 2026-08-20)
March 17, 2012	AMT	F	981	$63.34	$62,137	24,819 Direct	-3.80%	Disposed	179.9% (price as of 2026-08-20)
March 17, 2012	AMT	M	2,322	—	—	0 Direct	-100.00%	Disposed	(price as of 2026-08-20)
March 12, 2012	AMT	A	71,798	—	—	71,798 Direct	—	Acquired	(price as of 2026-08-20)
March 12, 2012	AMT	A	20,162	—	—	20,162 Direct	—	Acquired	(price as of 2026-08-20)
March 10, 2012	AMT	M	5,284	—	—	18,827 Direct	+39.02%	Acquired	(price as of 2026-08-20)
March 10, 2012	AMT	F	1,707	$62.22	$106,210	17,120 Direct	-9.07%	Disposed	184.9% (price as of 2026-08-20)
March 10, 2012	AMT	M	5,219	—	—	22,339 Direct	+30.48%	Acquired	(price as of 2026-08-20)
March 10, 2012	AMT	F	1,844	$62.22	$114,734	20,495 Direct	-8.25%	Disposed	184.9% (price as of 2026-08-20)
March 10, 2012	AMT	M	5,170	—	—	25,665 Direct	+25.23%	Acquired	(price as of 2026-08-20)
March 10, 2012	AMT	F	2,187	$62.22	$136,075	23,478 Direct	-8.52%	Disposed	184.9% (price as of 2026-08-20)
March 10, 2012	AMT	M	5,284	—	—	5,283 Direct	-50.00%	Disposed	(price as of 2026-08-20)
March 10, 2012	AMT	M	5,219	—	—	10,438 Direct	-33.33%	Disposed	(price as of 2026-08-20)
March 10, 2012	AMT	M	5,170	—	—	15,508 Direct	-25.00%	Disposed	(price as of 2026-08-20)
March 17, 2011	AMT	M	2,322	—	—	13,274 Direct	+21.20%	Acquired	(price as of 2026-08-20)
March 17, 2011	AMT	F	821	$51.04	$41,904	12,453 Direct	-6.19%	Disposed	247.4% (price as of 2026-08-20)
March 17, 2011	AMT	M	2,322	—	—	2,322 Direct	-50.00%	Disposed	(price as of 2026-08-20)
March 10, 2011	AMT	M	5,284	—	—	9,517 Direct	+124.83%	Acquired	(price as of 2026-08-20)
March 10, 2011	AMT	F	1,602	$50.78	$81,350	7,915 Direct	-16.83%	Disposed	249.1% (price as of 2026-08-20)
March 10, 2011	AMT	M	5,220	—	—	13,135 Direct	+65.95%	Acquired	(price as of 2026-08-20)
March 10, 2011	AMT	F	1,582	$50.78	$80,334	11,553 Direct	-12.04%	Disposed	249.1% (price as of 2026-08-20)

Showing latest 100 of 121 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
Oct. 30, 2018	AMT	Option to Purchase Common Stock	Common Stock (61,368)	$50.78	March 10, 2021	61,368	Disposed
Oct. 30, 2018	AMT	Option to Purchase Common Stock	Common Stock (71,798)	$62.00	March 12, 2022	71,798	Disposed
Oct. 30, 2018	AMT	Option to Purchase Common Stock	Common Stock (30,000)	$43.11	March 10, 2020	30,000	Disposed
June 27, 2017	AMT	Option to Purchase Common Stock	Common Stock (17,162)	$28.39	March 10, 2019	17,162	Disposed
July 12, 2016	AMT	Option to purchase common stock	Common Stock (50,000)	$44.92	Dec. 3, 2017	50,000	Disposed
July 11, 2016	AMT	Option to purchase common stock	Common Stock (50,000)	$44.92	Dec. 3, 2017	50,000	Disposed
July 8, 2016	AMT	Option to purchase common stock	Common Stock (50,000)	$44.92	Dec. 3, 2017	50,000	Disposed
March 10, 2015	AMT	Option to Purchase Common Stock	Common Stock (121,604)	$94.57	March 10, 2025	121,604	Acquired
March 12, 2014	AMT	Restricted Stock Units	Common Stock (5,041)	—	—	5,041	Disposed
March 11, 2014	AMT	Restricted Stock Units	Common Stock (4,552)	—	—	4,552	Disposed
March 10, 2014	AMT	Restricted Stock Units	Common Stock (5,219)	—	—	5,219	Disposed
March 10, 2014	AMT	Restricted Stock Units	Common Stock (5,169)	—	—	5,169	Disposed
March 10, 2014	AMT	Option to Purchase Common Stock	Common Stock (107,817)	$81.18	March 10, 2024	107,817	Acquired
March 10, 2014	AMT	Restricted Stock Units	Common Stock (19,710)	—	—	19,710	Acquired
March 12, 2013	AMT	Restricted Stock Units	Common Stock (5,041)	—	—	5,041	Disposed
March 11, 2013	AMT	Option to Purchase Common Stock	Common Stock (72,539)	$76.90	March 11, 2023	72,539	Acquired
March 11, 2013	AMT	Restricted Stock Units	Common Stock (18,206)	—	—	18,206	Acquired
March 10, 2013	AMT	Restricted Stock Units	Common Stock (5,283)	—	—	5,283	Disposed
March 10, 2013	AMT	Restricted Stock Units	Common Stock (5,219)	—	—	5,219	Disposed
March 10, 2013	AMT	Restricted Stock Units	Common Stock (5,170)	—	—	5,170	Disposed
Aug. 1, 2012	AMT	Option to Purchase Common Stock	Common Stock (30,000)	$43.11	March 10, 2020	30,000	Disposed
July 10, 2012	AMT	Option to Purchase Common Stock	Common Stock (32,500)	$37.70	March 17, 2018	32,500	Disposed
June 29, 2012	AMT	Option to Purchase Common Stock	Common Stock (51,488)	$28.39	March 10, 2019	51,488	Disposed
March 17, 2012	AMT	Restricted Stock Units	Common Stock (2,322)	—	—	2,322	Disposed
March 12, 2012	AMT	Option to Purchase Common Stock	Common Stock (71,798)	$62.00	March 12, 2022	71,798	Acquired
March 12, 2012	AMT	Restricted Stock Units	Common Stock (20,162)	—	—	20,162	Acquired
March 10, 2012	AMT	Restricted Stock Units	Common Stock (5,284)	—	—	5,284	Disposed
March 10, 2012	AMT	Restricted Stock Units	Common Stock (5,219)	—	—	5,219	Disposed
March 10, 2012	AMT	Restricted Stock Units	Common Stock (5,170)	—	—	5,170	Disposed
March 17, 2011	AMT	Restricted Stock Units	Class A Common Stock (2,322)	—	—	2,322	Disposed
March 10, 2011	AMT	Option to Purchase Class A Common Stock	Class A Common Stock (61,638)	$50.78	March 10, 2021	61,368	Acquired
March 10, 2011	AMT	Restricted Stock Units	Class A Common Stock (20,678)	—	—	20,678	Acquired
March 10, 2011	AMT	Restricted Stock Units	Class A Common Stock (5,284)	—	—	5,284	Disposed
March 10, 2011	AMT	Restricted Stock Units	Class A Common Stock (5,220)	—	—	5,220	Disposed
March 17, 2010	AMT	Restricted Stock Units	Class A Common Stock (2,323)	—	—	2,323	Disposed
March 10, 2010	AMT	Option to Purchase Class A Common Stock	Class A Common Stock (60,000)	$43.11	March 10, 2020	60,000	Acquired
March 10, 2010	AMT	Restricted Stock Units	Class A Common Stock (20,877)	—	—	20,877	Acquired
March 10, 2010	AMT	Restricted Stock Units	Class A Common Stock (5,284)	—	—	5,284	Disposed
March 17, 2009	AMT	Restricted Stock Units	Class A Common Stock (2,323)	—	—	2,323	Disposed
March 10, 2009	AMT	Option to Purchase Class A Common Stock	Class A Common Stock (68,650)	$28.39	March 10, 2019	68,650	Acquired
March 10, 2009	AMT	Restricted Stock Units	Class A Common Stock (21,135)	—	—	21,135	Acquired
March 17, 2008	AMT	Option to purchase Class A Common Stock	Class A Common Stock (32,500)	$37.70	March 17, 2018	32,500	Acquired
March 17, 2008	AMT	Restricted Stock Units	Class A Common Stock (9,290)	—	—	9,290	Acquired
Dec. 3, 2007	AMT	Option to Purchase Class A Common Stock	Class A Common Stock (150,000)	$44.92	Dec. 3, 2017	150,000	Acquired

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

Compensation (DEF 14A)

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

AMT

Fiscal year	Salary	Bonus	Stock awards	Option awards	Non-equity incentive	Pension change	Other	Total
2018	$649,347	—	—	—	$736,266	—	$277,467	$5,963,251
2017	$664,300	—	$4,000,060	—	$864,586	—	$208,417	$5,737,363
2016	$650,000	—	$3,670,013	—	$672,750	—	$145,671	$5,138,434

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