The public view is the crawlable proof. The same sourced dataset is available through REST and MCP for agents, research scripts, and back-office tools.
This stock page is the Follow view. The Build view lets your agent query OPEN owners, fund changes, insider filings, and source links through REST or MCP.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/stocks/OPEN"
Use Arkolith to show who owns OPEN, which funds added or reduced it, and which SEC filings prove each claim.
| # | Fund | Position value | Shares | Last move | As of | History |
|---|---|---|---|---|---|---|
| 1 | VANGUARD GROUP INC | $642.8M | 110.3M | ▲+62% Added · +42.1M sh | Q4 2025 | |
| 2 | MORGAN STANLEY | $481.0M | 102.8M | ▲+99% Added · +51.2M sh | Q1 2026 | |
| 3 | VANGUARD PORTFOLIO MANAGEMENT LLC | $327.9M | 70.1M | ▲New +70.1M sh | Q1 2026 | |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | $166.3M | 35.5M | ▲New +35.5M sh | Q1 2026 | |
| 5 | BlackRock, Inc. | $87.2M | 18.6M | ▲+4.1% Added · +729K sh | Q1 2026 | |
| 6 | JANE STREET GROUP, LLC | $68.9M | 14.7M | ▲+6.0% Added · +841K sh | Q1 2026 | |
| 7 | AMERICAN CENTURY COMPANIES INC | $66.5M | 14.2M | ▼−1.0% Reduced · −145K sh | Q1 2026 | |
| 8 | GEODE CAPITAL MANAGEMENT, LLC | $57.7M | 12.3M | ▲+6.2% Added · +717K sh | Q1 2026 | |
| 9 | RENAISSANCE TECHNOLOGIES LLC | $55.3M | 11.8M | ▼−70% Reduced · −27.5M sh | Q1 2026 | |
| 10 | D. E. Shaw & Co., Inc. | $52.6M | 11.2M | ▲+74% Added · +4.8M sh | Q1 2026 | |
| 11 | CHARLES SCHWAB INVESTMENT MANAGEMENT INC | $52.6M | 11.2M | ▼−3.9% Reduced · −454K sh | Q1 2026 | |
| 12 | MILLENNIUM MANAGEMENT LLC | $50.7M | 10.8M | ▲+123% Added · +6.0M sh | Q1 2026 | |
| 13 | Qube Research & Technologies Ltd | $47.5M | 10.2M | ▲+683% Added · +8.9M sh | Q1 2026 | |
| 14 | DIMENSIONAL FUND ADVISORS LP | $42.5M | 9.1M | ▲+97% Added · +4.5M sh | Q1 2026 | |
| 15 | CITADEL ADVISORS LLC | $37.6M | 8.0M | ▲+5.4% Added · +412K sh | Q1 2026 | |
| 16 | UBS Group AG | $33.6M | 7.2M | ▲+31% Added · +1.7M sh | Q1 2026 | |
| 17 | TWO SIGMA INVESTMENTS, LP | $31.7M | 6.8M | ▲+66% Added · +2.7M sh | Q1 2026 | |
| 18 | STATE STREET CORP | $28.0M | 6.0M | ▼−3.4% Reduced · −210K sh | Q1 2026 | |
| 19 | Marex Group plc | $23.1M | 4.9M | ▼−15% Reduced · −881K sh | Q1 2026 | |
| 20 | VANGUARD FIDUCIARY TRUST CO | $22.9M | 4.9M | ▲New +4.9M sh | Q1 2026 | |
| 21 | VOLORIDGE INVESTMENT MANAGEMENT, LLC | $20.2M | 4.3M | ▲+2.7% Added · +113K sh | Q1 2026 | |
| 22 | Trexquant Investment LP | $19.0M | 4.1M | ▲+127% Added · +2.3M sh | Q1 2026 | |
| 23 | GOLDMAN SACHS GROUP INC | $18.5M | 3.9M | ▲+151% Added · +2.4M sh | Q1 2026 | |
| 24 | SUSQUEHANNA INTERNATIONAL GROUP, LLP | $15.6M | 3.3M | ▲35× Added · +3.2M sh | Q1 2026 | |
| 25 | IEQ CAPITAL, LLC | $13.8M | 2.9M | —Held | Q1 2026 |
Holders and values reflect the 13F filers Arkolith currently tracks, not the entire institutional universe. Counts and totals are a floor, not the full institutional ownership.
| Date | Insider | Role | Action | Shares | Value |
|---|---|---|---|---|---|
| Jun 16, 2026 | Benson David C | Director | Sell (S) | 40K | $193K |
| Jun 11, 2026 | Rabois Keith | Director | Grant (A) | 42K | $0 |
| Jun 11, 2026 | Bain Adam | Director | Grant (A) | 42K | $0 |
| Jun 11, 2026 | HAMILTON DANA | Director | Grant (A) | 42K | $0 |
| Jun 11, 2026 | Wu Eric Chung-Wei | Director | Grant (A) | 42K | $0 |
| Jun 11, 2026 | Benson David C | Director | Grant (A) | 42K | $0 |
| Jun 11, 2026 | Feder Eric | Director | Grant (A) | 42K | $0 |
| Feb 17, 2026 | Rabois Keith | Director | Grant (A) | 15K | $0 |
| Feb 17, 2026 | Schwartz Christina | Chief Financial Officer | Sell (S) | 74K | $321K |
| Feb 17, 2026 | Bain Adam | Director | Grant (A) | 10K | $0 |
| Feb 17, 2026 | Feder Eric | Director | Grant (A) | 14K | $0 |
| Dec 31, 2025 | Schwartz Christina | Chief Financial Officer | Grant (A) | 1.7M | $0 |
| Class | 13F holders | Value held |
|---|---|---|
| OPENthis pagecs | 221 funds | $2.7B |
| OPENWwt | 76 funds | $3.5M |
| OPENLwt | 76 funds | $1.4M |
| OPENZwt | 70 funds | $639K |
Same issuer, multiple share classes. The consensus leaderboards count this company once across all classes; this is the per-class detail.
| Company | Co-held by | Combined value |
|---|---|---|
| MICROSOFT CORPMSFT | 126 funds | $44.2B |
| ALPHABET INC-CL AGOOGL | 125 funds | $27.6B |
| BROADCOM INCAVGO | 125 funds | $22.2B |
| TESLA INCTSLA | 125 funds | $12.8B |
| META PLATFORMS INC-CLASS AMETA | 124 funds | $19.9B |
| ELI LILLY & COLLY | 124 funds | $12.1B |
| PALANTIR TECHNOLOGIES INC-APLTR | 123 funds | $5.3B |
| NVIDIA CORPNVDA | 122 funds | $65.0B |
| APPLE INCAAPL | 122 funds | $49.4B |
| AMAZON.COM INCAMZN | 122 funds | $33.8B |
| COSTCO WHOLESALE CORPCOST | 122 funds | $7.9B |
| NETFLIX INCNFLX | 122 funds | $6.0B |
Ranked by how many of OPEN's institutional holders also hold each name, a cross-fund conviction signal. Via the MCP server (ticker.co_held).
13F holdings + Form 4 insider transactions + end-of-day price history + the live filing stream, joined for OPEN. Filings are public domain, sourced to SEC EDGAR; price series derived from end-of-day closes. Every panel above is one call to the Arkolith API & MCP server.