On this page, we present all of the funds holding ATRO from our database of 13F filers, detailed in the table below. The first column indicates the name of each of the funds holding ATRO, with a link to that fund's top holdings. The next columns indicate the amount of ATRO stock held by each of the funds holding ATRO, followed by the ATRO position size held by the fund, and lastly the date of the quarterly filing period the data represents. In total, we count 128 funds holding ATRO within the last two filing periods in our coverage universe of 13F filers, with the largest position size having been reported by Next Century Growth Investors LLC. For more details on the positions held by Next Century Growth Investors LLC (or by any of the other funds holding ATRO), click the fund name in the "Holder" column of the funds-holding-ATRO table below.

Holder	Amount	Position Size ($ in 1000's)	As of
Next Century Growth Investors LLC	2,222,747	$38,720	12/31/2023
ATRO	2,222,747	$38,720	12/31/2023
BlackRock Inc.	1,933,700	$33,685	12/31/2023
ATRO	1,933,700	$33,685	12/31/2023
325 Capital LLC	1,636,188	$28,502	12/31/2023
ATRO	1,636,188	$28,502	12/31/2023
ACK Asset Management LLC	1,529,000	$26,635	12/31/2023
ATRO	1,529,000	$26,635	12/31/2023
Vanguard Group Inc.	1,424,677	$24,818	12/31/2023
ATRO	1,424,677	$24,818	12/31/2023
Royce & Associates LP	963,004	$16,776	12/31/2023
ATRO	963,004	$16,776	12/31/2023
State Street Corp	919,532	$16,018	12/31/2023
ATRO	919,532	$16,018	12/31/2023
Dimensional Fund Advisors LP	892,049	$15,540	12/31/2023
ATRO	892,049	$15,540	12/31/2023
Bares Capital Management Inc.	814,692	$14,192	12/31/2023
ATRO	814,692	$14,192	12/31/2023
Geode Capital Management LLC	597,445	$10,409	12/31/2023
ATRO	597,445	$10,409	12/31/2023
Schonfeld Strategic Advisors LLC	592,485	$10,321	12/31/2023
ATRO	592,485	$10,321	12/31/2023
Praetorian PR LLC	515,500	$8,980	12/31/2023
ATRO	515,500	$8,980	12/31/2023
Senator Investment Group LP	508,774	$8,863	12/31/2023
ATRO	508,774	$8,863	12/31/2023
Minerva Advisors LLC	463,105	$8,072	12/31/2023
ATRO	463,105	$8,072	12/31/2023
Millennium Management LLC	348,715	$6,075	12/31/2023
ATRO	348,715	$6,075	12/31/2023
First Eagle Investment Management LLC	345,576	$6,020	12/31/2023
ATRO	345,576	$6,020	12/31/2023
Acadian Asset Management LLC	298,700	$5,202	12/31/2023
ATRO	298,700	$5,202	12/31/2023
Northern Trust Corp	244,690	$4,262	12/31/2023
ATRO	244,690	$4,262	12/31/2023
Morgan Stanley	236,787	$4,125	12/31/2023
ATRO	236,787	$4,125	12/31/2023
Teton Advisors Inc.	198,000	$3,449	12/31/2023
ATRO	198,000	$3,449	12/31/2023
Renaissance Technologies LLC	181,451	$3,161	12/31/2023
ATRO	181,451	$3,161	12/31/2023
Ameriprise Financial Inc.	124,037	$2,161	12/31/2023
ATRO	124,037	$2,161	12/31/2023
RBF Capital LLC	120,372	$2,097	12/31/2023
ATRO	120,372	$2,097	12/31/2023
Fisher Asset Management LLC	114,126	$1,988	12/31/2023
ATRO	114,126	$1,988	12/31/2023
Bank of New York Mellon Corp	100,922	$1,922	03/31/2024
ATRO	100,922	$1,922	03/31/2024
White Pine Capital LLC	104,472	$1,820	12/31/2023
ATRO	104,472	$1,820	12/31/2023
Invesco Ltd.	82,178	$1,432	12/31/2023
ATRO	82,178	$1,432	12/31/2023
Deutsche Bank AG	75,902	$1,322	12/31/2023
ATRO	75,902	$1,322	12/31/2023
Two Sigma Advisers LP	74,700	$1,301	12/31/2023
ATRO	74,700	$1,301	12/31/2023
Charles Schwab Investment Management Inc.	72,307	$1,260	12/31/2023
ATRO	72,307	$1,260	12/31/2023
Nuveen Asset Management LLC	69,536	$1,211	12/31/2023
ATRO	69,536	$1,211	12/31/2023
Rhumbline Advisers	68,971	$1,201	12/31/2023
ATRO	68,971	$1,201	12/31/2023
Tudor Investment Corp Et Al	63,945	$1,114	12/31/2023
ATRO	63,945	$1,114	12/31/2023
FMR LLC	63,729	$1,110	12/31/2023
ATRO	63,729	$1,110	12/31/2023
Goldman Sachs Group Inc.	63,649	$1,109	12/31/2023
ATRO	63,649	$1,109	12/31/2023
Citadel Advisors LLC		$1,096	12/31/2023
ATRO	51,453	$896	12/31/2023
Call	25,500	$444	12/31/2023
Put	14,000	$244	12/31/2023
Los Angeles Capital Management & Equity Research Inc.	53,401	$1,017	03/31/2024
ATRO	53,401	$1,017	03/31/2024
Gabelli Funds LLC	56,628	$986	12/31/2023
ATRO	56,628	$986	12/31/2023
D. E. Shaw & Co. Inc.	54,979	$958	12/31/2023
ATRO	54,979	$958	12/31/2023
Kennedy Capital Management Inc.	54,337	$947	12/31/2023
ATRO	54,337	$947	12/31/2023
Swiss National Bank	49,700	$866	12/31/2023
ATRO	49,700	$866	12/31/2023
JPMorgan Chase & Co.	47,073	$820	12/31/2023
ATRO	47,073	$820	12/31/2023
Advisory Research Inc.	45,596	$794	12/31/2023
ATRO	45,596	$794	12/31/2023
Cubist Systematic Strategies LLC	45,563	$794	12/31/2023
ATRO	45,563	$794	12/31/2023
Connor Clark & Lunn Investment Management Ltd.	41,623	$725	12/31/2023
ATRO	41,623	$725	12/31/2023
Barclays PLC	41,105	$716	12/31/2023
ATRO	41,105	$716	12/31/2023
Credit Suisse AG	40,646	$708	12/31/2023
ATRO	40,646	$708	12/31/2023
BNP Paribas Arbitrage SA	38,931	$678	12/31/2023
ATRO	38,931	$678	12/31/2023
Legal & General Group Plc	37,867	$660	12/31/2023
ATRO	37,867	$660	12/31/2023
UBS Group AG	36,458	$635	12/31/2023
ATRO	36,458	$635	12/31/2023
Two Sigma Investments LP	35,199	$613	12/31/2023
ATRO	35,199	$613	12/31/2023
Bank of America Corp DE	31,371	$546	12/31/2023
ATRO	31,371	$546	12/31/2023
Federated Hermes Inc.	28,780	$501	12/31/2023
ATRO	28,780	$501	12/31/2023
AQR Capital Management LLC	28,009	$488	12/31/2023
ATRO	28,009	$488	12/31/2023
California State Teachers Retirement System	26,769	$466	12/31/2023
ATRO	26,769	$466	12/31/2023
Janney Montgomery Scott LLC	26,702	$465	12/31/2023
ATRO	26,702	$465	12/31/2023
Royal Bank of Canada	26,641	$464	12/31/2023
ATRO	26,641	$464	12/31/2023
State of Wyoming	26,493	$462	12/31/2023
ATRO	26,493	$462	12/31/2023
Raymond James & Associates	21,972	$418	03/31/2024
ATRO	21,972	$418	03/31/2024
Putnam Investments LLC	23,850	$415	12/31/2023
ATRO	23,850	$415	12/31/2023
Advisors Asset Management Inc.	23,295	$406	12/31/2023
ATRO	23,295	$406	12/31/2023
Russell Investments Group Ltd.	21,800	$380	12/31/2023
ATRO	21,800	$380	12/31/2023
Algert Global LLC	21,660	$377	12/31/2023
ATRO	21,660	$377	12/31/2023
Occudo Quantitative Strategies LP	21,554	$375	12/31/2023
ATRO	21,554	$375	12/31/2023
Sierra Summit Advisors LLC	19,677	$343	12/31/2023
ATRO	19,677	$343	12/31/2023
Jane Street Group LLC	19,476	$339	12/31/2023
ATRO	19,476	$339	12/31/2023
GSA Capital Partners LLP	18,020	$314	12/31/2023
ATRO	18,020	$314	12/31/2023
Franklin Resources Inc.	17,084	$298	12/31/2023
ATRO	17,084	$298	12/31/2023
State of Wisconsin Investment Board	16,800	$293	12/31/2023
ATRO	16,800	$293	12/31/2023
Sontag Advisory LLC	15,266	$266	12/31/2023
ATRO	15,266	$266	12/31/2023
SG Americas Securities LLC	14,900	$260	12/31/2023
ATRO	14,900	$260	12/31/2023
Alliancebernstein L.P.	14,590	$254	12/31/2023
ATRO	14,590	$254	12/31/2023
MetLife Investment Management LLC	13,979	$244	12/31/2023
ATRO	13,979	$244	12/31/2023
Hennion & Walsh Asset Management Inc.	12,569	$239	03/31/2024
ATRO	12,569	$239	03/31/2024
Walleye Capital LLC	13,695	$239	12/31/2023
ATRO	13,695	$239	12/31/2023
Janus Henderson Group PLC	13,533	$236	12/31/2023
ATRO	13,533	$236	12/31/2023
American International Group Inc.	13,073	$228	12/31/2023
ATRO	13,073	$228	12/31/2023
Gamco Investors INC. ET AL	12,800	$223	12/31/2023
ATRO	12,800	$223	12/31/2023
Hunter Associates Investment Management LLC	12,000	$209	12/31/2023
ATRO	12,000	$209	12/31/2023
Clear Rock Advisors LLC	11,119	$204	12/31/2023
ATRO	11,119	$204	12/31/2023
Mirae Asset Global Investments Co. Ltd.	11,672	$203	12/31/2023
ATRO	11,672	$203	12/31/2023
Bristlecone Advisors LLC	10,280	$196	03/31/2024
ATRO	10,280	$196	03/31/2024
Voya Investment Management LLC	11,089	$193	12/31/2023
ATRO	11,089	$193	12/31/2023
Bessemer Group Inc.	11,000	$192	12/31/2023
ATRO	11,000	$192	12/31/2023
The Manufacturers Life Insurance Company	10,630	$185	12/31/2023
ATRO	10,630	$185	12/31/2023
Jump Financial LLC	10,500	$183	12/31/2023
ATRO	10,500	$183	12/31/2023
Lazard Asset Management LLC	10,300	$179	12/31/2023
ATRO	10,300	$179	12/31/2023
Wells Fargo & Company MN	9,996	$174	12/31/2023
ATRO	9,996	$174	12/31/2023
Citigroup Inc.	9,801	$171	12/31/2023
ATRO	9,801	$171	12/31/2023
New York State Common Retirement Fund	9,220	$161	12/31/2023
ATRO	9,220	$161	12/31/2023
Tower Research Capital LLC TRC	9,191	$160	12/31/2023
ATRO	9,191	$160	12/31/2023
DekaBank Deutsche Girozentrale	8,146	$153	03/31/2024
ATRO	8,146	$153	03/31/2024
Susquehanna International Group LLP		$149	12/31/2023
Put	25,300	$441	12/31/2023
ATRO	21,860	$381	12/31/2023
Call	12,000	$209	12/31/2023
West Branch Capital LLC	5,700	$109	03/31/2024
ATRO	5,700	$109	03/31/2024
RiverPark Advisors LLC	5,815	$101	12/31/2023
ATRO	5,815	$101	12/31/2023
Zurcher Kantonalbank Zurich Cantonalbank	5,228	$100	03/31/2024
ATRO	5,228	$100	03/31/2024
Public Employees Retirement Association of Colorado	5,404	$94	12/31/2023
ATRO	5,404	$94	12/31/2023
Arcadia Investment Management Corp MI	4,881	$93	03/31/2024
ATRO	4,881	$93	03/31/2024
Smithfield Trust Co.	4,527	$79	12/31/2023
ATRO	4,527	$79	12/31/2023
Psagot Value Holdings Ltd. Israel	4,352	$77	12/31/2023
ATRO	4,352	$77	12/31/2023
Great West Life Assurance Co. Can	3,945	$68	12/31/2023
ATRO	3,945	$68	12/31/2023
MCF Advisors LLC	2,647	$50	03/31/2024
ATRO	2,647	$50	03/31/2024
Ameritas Investment Partners Inc.	2,722	$47	12/31/2023
ATRO	2,722	$47	12/31/2023
Advisor Group Holdings Inc.	2,544	$44	12/31/2023
ATRO	2,544	$44	12/31/2023
Metropolitan Life Insurance Co NY	1,404	$24	12/31/2023
ATRO	1,404	$24	12/31/2023
CNB Bank	1,072	$19	12/31/2023
ATRO	1,072	$19	12/31/2023
Qube Research & Technologies Ltd	1,054	$18	12/31/2023
ATRO	1,054	$18	12/31/2023
Amalgamated Bank	869	$17	03/31/2024
ATRO	869	$17	03/31/2024
Ancora Advisors LLC	750	$13	12/31/2023
ATRO	750	$13	12/31/2023
Nisa Investment Advisors LLC	610	$11	12/31/2023
ATRO	610	$11	12/31/2023
Quarry LP	430	$7	12/31/2023
ATRO	430	$7	12/31/2023
Simplex Trading LLC		$4	03/31/2024
ATRO	1,292	$24	03/31/2024
Put	1,100	$20	03/31/2024
Allspring Global Investments Holdings LLC	216	$4	03/31/2024
ATRO	216	$4	03/31/2024
National Bank of Canada FI	250	$4	12/31/2023
ATRO	250	$4	12/31/2023
Quadrant Capital Group LLC	214	$4	12/31/2023
ATRO	214	$4	12/31/2023
EverSource Wealth Advisors LLC	250	$4	12/31/2023
ATRO	250	$4	12/31/2023
Lindbrook Capital LLC	83	$2	03/31/2024
ATRO	83	$2	03/31/2024
US Bancorp DE	102	$2	12/31/2023
ATRO	102	$2	12/31/2023
CWM LLC	30	$1	03/31/2024
ATRO	30	$1	03/31/2024
Allworth Financial LP	31	$1	03/31/2024
ATRO	31	$1	03/31/2024
Comerica Bank	52	$1	12/31/2023
ATRO	52	$1	12/31/2023
Raleigh Capital Management Inc.	55	$1	12/31/2023
ATRO	55	$1	12/31/2023
GAMMA Investing LLC	21	$0	03/31/2024
ATRO	21	$0	03/31/2024
Huntington National Bank	1	$0	12/31/2023
ATRO	1	$0	12/31/2023
The PNC Financial Services Group Inc.	5	$0	12/31/2023
ATRO	5	$0	12/31/2023
Proequities Inc.		$0	12/31/2023
Put	0	$0	12/31/2023
ATRO	0	$0	12/31/2023
Call	0	$0	12/31/2023
Signaturefd LLC	13	$0	12/31/2023
ATRO	13	$0	12/31/2023
Parallel Advisors LLC	28	$0	12/31/2023
ATRO	28	$0	12/31/2023
Group One Trading L.P.	100	$-22	12/31/2023
Put	1,400	$24	12/31/2023
Call	100	$2	12/31/2023