Ticker · CUSIP 04963C209
Holders (tracked)
10
Combined shares
5,786,008
Combined value
$228.89M
Last close
$29.72
Quarter
2025Q4
Price · 1Y$29.72-2.29 (-7.15%)H $42.41 · L $28.05 · Avg Vol 568K
Congress buy
Tracked holders · last 8 quarters
+2 vs previous quarter over the last 8.
Price is -24.9% vs the avg quarter-end implied price across tracked holders.
SEC event timeline
19 events
- T. Rowe Price added2026-02-17+2,121 shares · 2025Q4Position
- Wellington Management trimmed2026-02-17−374,096 shares · 2025Q4Position
- Two Sigma Investments trimmed2026-02-17−72,376 shares · 2025Q4Position
- AQR Capital Management added2026-02-17+15,784 shares · 2025Q4Position
- Izzy Englander (Millennium Mgmt) trimmed2026-02-17−189,465 shares · 2025Q4Position
- Steve Cohen (Point72) opened position2026-02-17+277,924 shares · 2025Q4Position
- Ken Griffin (Citadel Advisors) added2026-02-17+197,242 shares · 2025Q4Position
- Renaissance Technologies added2026-02-12+63,100 shares · 2025Q4Position
- Norges Bank (Norway SWF) opened position2026-02-10+214,016 shares · 2025Q4Position
- +116,609 shares · 2025Q4Position
- Izzy Englander (Millennium Mgmt) trimmed2025-11-14−6,805 shares · 2025Q3Position
- Two Sigma Investments added2025-11-14+40,962 shares · 2025Q3Position
- D.E. Shaw & Co. exited2025-11-14−7,776 shares · 2025Q3Position
- AQR Capital Management added2025-11-14+16,459 shares · 2025Q3Position
- T. Rowe Price added2025-11-14+2,145 shares · 2025Q3Position
- Wellington Management added2025-11-14+322,818 shares · 2025Q3Position
- Renaissance Technologies trimmed2025-11-13−118,900 shares · 2025Q3Position
- Norges Bank (Norway SWF) exited2025-11-13−10,438 shares · 2025Q3Position
- Norges Bank (Norway SWF) trimmed2025-11-12−25,868 shares · 2024Q3Position
Insider activity
No insider transactions in the last 30 days.
Follow-the-investor returns
If you'd copied each holder of ATRC…
Cost basis inferred from each manager's quarter-over-quarter position changes. Sorted by % return on the position they're still holding.
| Investor | First in | Cost basis | Return | Position value today |
|---|---|---|---|---|
| Izzy Englander (Millennium Mgmt) | 2016Q1 | $27.02 | +10.0% | $4.9M |
| T. Rowe Price | 2018Q1 | $29.12 | +2.1% | $1.5M |
| Two Sigma Investments | 2016Q1 | $31.10 | -4.4% | $11.3M |
| Steve Cohen (Point72) | 2017Q2 | $32.26 | -7.9% | $8.3M |
| AQR Capital Management | 2016Q1 | $32.42 | -8.3% | $3.0M |
| Wellington Management | 2016Q1 | $33.80 | -12.1% | $116.4M |
| Renaissance Technologies | 2016Q1 | $35.09 | -15.3% | $9.6M |
| Ken Griffin (Citadel Advisors) | 2016Q1 | $39.35 | -24.5% | $7.2M |
| First Eagle Investment Management | 2025Q4 | $39.56 | -24.9% | $3.5M |
| Norges Bank (Norway SWF) | 2020Q3 | $40.61 | -26.8% | $6.4M |
Who moved on this name in 2025Q4
Position changes reported for the latest quarter, grouped by direction.
New positions3
- Steve Cohen (Point72)+277,924$11.0M
- Norges Bank (Norway SWF)+214,016$8.5M
- First Eagle Investment Management+116,609$4.6M
Added to4
- Ken Griffin (Citadel Advisors)+197,242$7.8M
- Renaissance Technologies+63,100$2.5M
- AQR Capital Management+15,784$624K
- T. Rowe Price+2,121$84
Trimmed3
- Wellington Management−374,096$14.8M
- Izzy Englander (Millennium Mgmt)−189,465$7.5M
- Two Sigma Investments−72,376$2.9M
Exited0
—
Institutional ownership over time
Distinct super-investors holding this ticker · combined dollar value, by quarter.
| Quarter | Holders | Combined value |
|---|---|---|
| 2022Q1 | 11 | $25.67B |
| 2022Q2 | 13 | $15.54B |
| 2022Q3 | 12 | $207.7M |
| 2022Q4 | 14 | $333.0M |
| 2023Q1 | 13 | $351.3M |
| 2023Q2 | 14 | $411.8M |
| 2023Q3 | 13 | $255.3M |
| 2023Q4 | 13 | $214.3M |
| 2024Q1 | 14 | $223.3M |
| 2024Q2 | 14 | $196.0M |
| 2024Q3 | 12 | $92.6M |
| 2024Q4 | 10 | $50.1M |
| 2025Q1 | 11 | $103.7M |
| 2025Q2 | 10 | $176.8M |
| 2025Q3 | 8 | $195.4M |
| 2025Q4 | 10 | $228.9M |
Congress members trading this stock
| Date | Member | Type | Amount range | Filing |
|---|---|---|---|---|
| 2026-03-03 | Gilbert Cisneros | Buy | $1K – $15K | PDF ↗ |
| 2025-05-06 | Gilbert Cisneros | Buy | $1K – $15K | PDF ↗ |
Who owns ATRC
10 super-investors · 2025Q4
Tracked stake
5.79M
shares
Combined value
$229M
% of shares outstanding
—
shares-out unknown
Quarter action mix
New3Added4Trim3
| # | Manager | Shares | Value |
|---|---|---|---|
| 1 | Wellington Management | 3.92M | $155M |
| 2 | Two Sigma Investments | 380.5K | $15M |
| 3 | Renaissance Technologies | 321.9K | $13M |
| 4 | Steve Cohen Point72 | 277.9K | $11M |
| 5 | Ken Griffin Citadel Advisors | 242.7K | $10M |
| 6 | Norges Bank Norway SWF | 214.0K | $8M |
| 7 | Izzy Englander Millennium Mgmt | 163.8K | $6M |
| 8 | First Eagle Investment Management | 116.6K | $5M |
| 9 | AQR Capital Management | 100.0K | $4M |
| 10 | T. Rowe Price | 50.6K | $2M |
Recent moves
20 transactions
- +2,121 · 2025Q4
- −189,465 · 2025Q4
- +197,242 · 2025Q4
- −72,376 · 2025Q4
- +15,784 · 2025Q4
- +277,924 · 2025Q4
- −374,096 · 2025Q4
- +63,100 · 2025Q4
- +214,016 · 2025Q4
- +116,609 · 2025Q4
- +322,818 · 2025Q3
- +16,459 · 2025Q3
- +2,145 · 2025Q3
- +40,962 · 2025Q3
- SOLDD.E. Shaw & Co.−7,776 · 2025Q3
- −6,805 · 2025Q3
- −118,900 · 2025Q3
- −10,438 · 2025Q3
- −25,868 · 2024Q3
- −558,348 · 2025Q2
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