- Quarter end
- 31 Dec 2025
- the date the book describes
- Filed
- 19 Feb 2026
- latest of these filings; the earliest 5 Feb 2026
- Managers listing it
- 24
- at least, of 95 tracked, among listed positions
- Comparable managers
- 92
- filed both Q3 2025 and Q4 2025; 1 listed it in both
- Shares listed
- 6,654,008
- combined, among listed positions
- Reported value
- $329m
- combined, at the quarter end
Among the 92 comparable managers: 14 buyers (opened or added shares) and 13 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was +1,321,449.
Managers listing ROCK in Q4 2025
24 of 24 holders
Largest increases and reductions, by shares
Increases
- AllianceBernstein LPexisting position · 1,714,322 shares now+1,177,654
- Fidelity (FMR LLC)existing position · 3,696,450 shares now+581,382
- Jane Street Group LLCnew position · 95,065 shares now+95,065
- ExodusPoint Capital Management LPnew position · 37,801 shares now+37,801
- Millennium Management LLCexisting position · 49,445 shares now+37,738
Reductions
- Citadel Advisors LLCexisting position · 93,317 shares now-91,428
- Renaissance Technologies LLCexisting position · 39,100 shares now-65,500
- AQR Capital Management LLCexisting position · 37,422 shares now-57,143
- Arrowstreet Capital LPexisting position · 43,480 shares now-38,263
- Verition Fund Management LLCexisting position · 13,164 shares now-7,765
New positions and exits
New (5)
Exited (4)
- Wellington Management Group LLPwas $26m
- Man Group PLCwas $782k
- Schonfeld Strategic Advisors LLCwas $684k
- Squarepoint Ops LLCwas $520k
Ownership over time
Tracked managers listing it, at least.
| Quarter | Holders | Reported value | Buyers | Sellers |
|---|---|---|---|---|
| Q4 2015 | 2 | $29m | n.a. | n.a. |
| Q1 2016 | 1 | $30m | n.a. | n.a. |
| Q2 2016 | 1 | $29m | n.a. | n.a. |
| Q3 2016 | 1 | $36m | n.a. | n.a. |
| Q4 2016 | 2 | $53m | n.a. | n.a. |
| Q1 2017 | 1 | $49m | n.a. | n.a. |
| Q2 2017 | 1 | $3.2m | n.a. | n.a. |
| Q3 2017 | 3 | $5.3m | n.a. | n.a. |
| Q4 2017 | 2 | $3.8m | n.a. | n.a. |
| Q1 2018 | 1 | $1.3m | n.a. | n.a. |
| Q2 2018 | 1 | $5.3m | n.a. | n.a. |
| Q3 2018 | 1 | $9.6m | n.a. | n.a. |
| Q3 2019 | 2 | $11m | n.a. | n.a. |
| Q4 2019 | 4 | $13m | n.a. | n.a. |
| Q1 2020 | 2 | $16m | n.a. | n.a. |
| Q2 2020 | 1 | $2.5m | n.a. | n.a. |
| Q3 2020 | 3 | $237m | n.a. | n.a. |
| Q4 2020 | 3 | $269m | n.a. | n.a. |
| Q1 2021 | 3 | $333m | n.a. | n.a. |
| Q2 2021 | 2 | $3.7m | n.a. | n.a. |
| Q3 2021 | 2 | $4.1m | n.a. | n.a. |
| Q4 2021 | 2 | $4.6m | n.a. | n.a. |
| Q1 2022 | 3 | $6.3m | n.a. | n.a. |
| Q2 2022 | 4 | $8.8m | n.a. | n.a. |
| Q3 2022 | 3 | $8.0m | n.a. | n.a. |
| Q4 2022 | 2 | $6.1m | n.a. | n.a. |
| Q1 2023 | 2 | $8.0m | n.a. | n.a. |
| Q2 2023 | 3 | $12m | n.a. | n.a. |
| Q3 2023 | 4 | $40m | n.a. | n.a. |
| Q4 2023 | 6 | $79m | 2 | 4 |
| Q1 2024 | 5 | $67m | 3 | 2 |
| Q2 2024 | 4 | $70m | 2 | 2 |
| Q3 2024 | 2 | $11m | 0 | 2 |
| Q4 2024 | 1 | $5.1m | 0 | 2 |
| Q1 2025 | 2 | $123m | 2 | 0 |
| Q2 2025 | 2 | $8.9m | 2 | 0 |
| Q3 2025 | 1 | $5.7m | 0 | 1 |
| Q4 2025 | 3 | $90m | 14 | 13 |
| Q1 2026 | 4 | $115m | 14 | 11 |
| Q2 2026 | 3 | $95m | 18 | 8 |
Compare with…
Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.
ROCK and LIN →ROCK and GLW →ROCK and HWM →Choose a stock to compare with ROCK →
How much of the picture this is
A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.
Which funds own ROCK, latest filings →Back to the 13F Explorer →