Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in CALX held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | 11.2M | $546.4M | -2.7% | 17.263% | 0.01% |
| 2 | VANGUARD PORTFOLIO MANAGEMENT LLC | 5.5M | $271.1M | — | 8.565% | 0.01% |
| 3 | ALLIANCEBERNSTEIN L.P. | 3.3M | $172.1M | +122.3% | 5.032% | 0.06% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 2.7M | $131.6M | — | 4.158% | 0.00% |
| 5 | STATE STREET CORP | 2.6M | $127.6M | +10.1% | 4.028% | 0.00% |
| 6 | MILLENNIUM MANAGEMENT LLC | 1.9M | $93.3M | +32.0% | 2.947% | 0.06% |
| 7 | CONGRESS ASSET MANAGEMENT CO /MA | 1.6M | $80.6M | +13.6% | 2.545% | 0.58% |
| 8 | WESTFIELD CAPITAL MANAGEMENT CO LP | 1.5M | $75.7M | +35.0% | 2.393% | 0.32% |
| 9 | GEODE CAPITAL MANAGEMENT, LLC | 1.4M | $70.3M | -0.7% | 2.222% | 0.00% |
| 10 | DIMENSIONAL FUND ADVISORS LP | 1.2M | $59.7M | +28.4% | 1.886% | 0.01% |
| 11 | LOOMIS SAYLES & CO L P | 840K | $41.2M | +6.4% | 1.300% | 0.06% |
| 12 | GILDER GAGNON HOWE & CO LLC | 779K | $38.2M | -12.3% | 1.206% | 0.46% |
| 13 | PARADIGM CAPITAL MANAGEMENT INC/NY | 768K | $37.6M | +14.2% | 1.189% | 1.44% |
| 14 | BANK OF AMERICA CORP /DE/ | 750K | $36.7M | +63.3% | 1.161% | 0.00% |
| 15 | MORGAN STANLEY | 712K | $34.9M | +14.3% | 1.102% | 0.00% |
| 16 | MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. | 697K | $34.1M | -9.0% | 1.079% | 0.05% |
| 17 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | 682K | $33.4M | +1.3% | 1.056% | 0.01% |
| 18 | UBS Group AG | 645K | $31.6M | +79.7% | 0.999% | 0.00% |
| 19 | NORTHERN TRUST CORP | 610K | $29.9M | +2.4% | 0.944% | 0.00% |
| 20 | Harvey Partners, LLC | 573K | $28.0M | +7.3% | 0.886% | 2.28% |
| 21 | NOMURA ASSET MANAGEMENT INTERNATIONAL INC. | 557K | $27.3M | +43.6% | 0.862% | 0.05% |
| 22 | ARROWSTREET CAPITAL, LIMITED PARTNERSHIP | 551K | $27.0M | -56.9% | 0.853% | 0.01% |
| 23 | RENAISSANCE TECHNOLOGIES LLC | 543K | $26.6M | +17.2% | 0.841% | 0.04% |
| 24 | WELLINGTON MANAGEMENT GROUP LLP | 535K | $26.2M | -16.4% | 0.827% | 0.00% |
| 25 | Artisan Partners Limited Partnership | 530K | $26.0M | -10.2% | 0.820% | 0.04% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). “% of Fund” shows how much of that investor’s total 13F portfolio is invested in CALX — a direct measure of their conviction.
Filings activity in CALX during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings · Δ columns show change vs prior quarter
| Quarter | Inst. Holders | Δ Holders | Ownership % | Δ Ownership | Total 13F Value | Δ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 302 | 7.4% | 114.18% | 4.81 pp | $2.83B | 4.0% |
| Q4 2025 | 326 | +6.2% | 118.99% | 11.96 pp | $2.95B | 9.1% |
| Q3 2025 | 307 | +5.1% | 130.95% | +17.22 pp | $3.25B | +15% |
| Q2 2025 | 292 | +15% | 113.73% | +34.50 pp | $2.82B | +44% |
| Q1 2025 | 254 | +2.0% | 79.23% | +0.08 pp | $1.97B | +0.1% |
| Q4 2024 | 249 | +5.5% | 79.15% | 9.44 pp | $1.96B | 11% |
| Q3 2024 | 236 | 5.6% | 88.59% | 1.12 pp | $2.20B | 1.2% |
| Q2 2024 | 250 | — | 89.71% | — | $2.23B | — |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Δ columns compare to the immediately prior filed quarter.
Quick answers to the most common questions about buying CALX stock.
Based on Q1 2026 13F filings, institutional ownership of Calix, Inc. stands at 114.2%, held across 302 reporting institutions.
BlackRock, Inc. is the largest reported institutional holder of CALX, with approximately 11,153,403 shares worth $0.55B as of Q1 2026.
Yes — 2 widely-followed marquee investors appear among the top 25 institutional holders of CALX, including MILLENNIUM MANAGEMENT LLC, RENAISSANCE TECHNOLOGIES LLC.
Our composite Smart Money Score for CALX is 38 out of 100 (Bearish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
47 institutions opened new positions in CALX during Q1 2026, while 71 fully exited. 87 added to existing positions and 166 trimmed.
CALX institutional ownership fell by 4.81 percentage points quarter-over-quarter, with a net change of -24 holders.
The top 10 institutions account for 57.5% of all reported 13F value in CALX, and the top 25 account for 74.4%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.
Calix, Inc. (CALX) Institutional Ownership