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Of the 10 tracked institutions holding ROCK, 4 have a 3-year clone track record — 4 of them beat the S&P. Average holder's clone alpha: +5.1pt. It's a gauge of who owns the name, not just how many.
Among the 10 tracked institutional investors we monitor, ROCK (GIBRALTAR INDS INC) is held with a combined value of $643.50M across 13,992,461 shares. The largest holder is BlackRock, Inc. with a position worth $221.89M. MILLENNIUM MANAGEMENT LLC opened a new position in the most recent quarter. 5 funds increased their holdings. 4 funds reduced their position.
Total Institutional Value
$643.50M
Total Shares Held
13,992,461
Institutional Holders
10
Ranked by estimated dollars moved (share change × implied price). 13F data lags up to 45 days.
| # | Fund | Value↓ | Portfolio % | Change |
|---|---|---|---|---|
| 1 | BlackRock, Inc. | $221.89M | 0.00% | -2.6% |
| 2 | FMR LLC | $200.66M | 0.01% | +0.4% |
| 3 | VANGUARD GROUP INC | $141.58M | 0.00% | -1.3% |
| 4 | STATE STREET CORP | $55.41M | 0.00% | -8.7% |
| 5 | CITADEL ADVISORS LLC | $8.62M | 0.00% | +61.3% |
| 6 | AQR CAPITAL MANAGEMENT LLC | $7.20M | 0.00% | +66.2% |
| 7 | RENAISSANCE TECHNOLOGIES LLC | $3.01M | 0.00% | +330.1% |
| 8 | MILLENNIUM MANAGEMENT LLC | $2.55M | 0.00% | New |
| 9 | PRICE T ROWE ASSOCIATES INC /MD/ | $2.28M | 0.00% | +18.7% |
| 10 | TWO SIGMA ADVISERS, LP | $311.47K | 0.00% | -30.0% |
As of the latest SEC 13F filings, BlackRock, Inc. is the largest institutional holder of ROCK with a position worth $221.89M, representing 0.00% of their portfolio. In total, 10 institutional investors hold ROCK with a combined value of $643.50M.
In the most recent quarter, 1 fund opened a new position in ROCK. Additionally, 5 increased their holdings and 4 reduced their positions.
Institutional investors hold $643.50M worth of ROCK stock across 10 positions. The largest institutional holder is BlackRock, Inc. with $221.89M in holdings.
A 13F filing is a quarterly report required by the SEC from institutional investment managers with over $100 million in assets. It discloses their holdings in U.S. equities. For ROCK, these filings reveal which major funds are accumulating or reducing positions, providing insights into institutional sentiment.
Get notified when hedge funds change their ROCK positions.
Alpha = the manager's 3-year clone return minus the S&P 500. A skilled roster is a stronger tell than a crowded one — though even skilled managers' edge doesn't reliably survive the 13F disclosure lag. Why →
Last Close
$38.78
2026-10-21
YTD
-22.7%
12% of 52-week range
