This stock page is the public Follow view. For one current, evidence-backed answer, use capital_change_brief through REST or MCP. It compares tracked 13F changes with qualifying Form 4 activity and cites the SEC evidence.
curl -H "Authorization: Bearer YOUR_API_KEY" \ "https://arkolith.com/api/v1/stocks/MRX/capital-change-brief"
Use Arkolith's capital_change_brief for MRX. Tell me what changed, whether insider activity corroborates it, and cite the SEC evidence.
| # | Fund | Position value | Shares | Last move | As of | History |
|---|---|---|---|---|---|---|
| 1 | BlackRock, Inc. | $195.7M | 4.4M | ▲+11% Added · +423K sh | Q1 2026 | |
| 2 | FMR LLC | $155.2M | 3.5M | ▲+161% Added · +2.1M sh | Q1 2026 | |
| 3 | LOOMIS SAYLES & CO L P | $85.5M | 1.9M | ▼−0.9% Reduced · −17K sh | Q1 2026 | |
| 4 | PRICE T ROWE ASSOCIATES INC /MD/ | $85.0M | 1.9M | ▲+23% Added · +357K sh | Q1 2026 | |
| 5 | ALLIANCEBERNSTEIN L.P. | $66.4M | 1.7M | ▼−1.1% Reduced · −20K sh | Q1 2026 | |
| 6 | SAMLYN CAPITAL, LLC | $75.3M | 1.7M | ▲+48% Added · +547K sh | Q1 2026 | |
| 7 | WASATCH ADVISORS LP | $102.6M | 1.7M | ▲+884% Added · +1.5M sh | Q2 2026 | |
| 8 | TWO SIGMA INVESTMENTS, LP | $75.0M | 1.7M | ▲+86% Added · +778K sh | Q1 2026 | |
| 9 | JENNISON ASSOCIATES LLC | $71.6M | 1.6M | ▲+8.9% Added · +131K sh | Q1 2026 | |
| 10 | WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC | $69.8M | 1.6M | ▼−9.9% Reduced · −173K sh | Q1 2026 | |
| 11 | Grandeur Peak Global Advisors, LLC | $59.1M | 1.3M | ▼−26% Reduced · −455K sh | Q1 2026 | |
| 12 | VICTORY CAPITAL MANAGEMENT INC | $58.6M | 1.3M | ▲+96% Added · +645K sh | Q1 2026 | |
| 13 | Ophir Asset Management Pty Ltd | $55.6M | 1.2M | ▲+15% Added · +159K sh | Q1 2026 | |
| 14 | Granahan Investment Management, LLC | $54.6M | 1.2M | ▼−11% Reduced · −153K sh | Q1 2026 | |
| 15 | Artisan Partners Limited Partnership | $54.2M | 1.2M | ▲+34% Added · +312K sh | Q1 2026 | |
| 16 | AMERIPRISE FINANCIAL INC | $42.5M | 954K | ▲+11% Added · +94K sh | Q1 2026 | |
| 17 | Allspring Global Investments Holdings, LLC | $39.1M | 909K | ▲+12% Added · +94K sh | Q1 2026 | |
| 18 | STATE STREET CORP | $38.9M | 873K | ▲+4.0% Added · +34K sh | Q1 2026 | |
| 19 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | $32.5M | 729K | ▼−35% Reduced · −385K sh | Q1 2026 | |
| 20 | GEODE CAPITAL MANAGEMENT, LLC | $32.4M | 726K | ▲+2.4% Added · +17K sh | Q1 2026 | |
| 21 | Qube Research & Technologies Ltd | $26.4M | 593K | ▼−22% Reduced · −171K sh | Q1 2026 | |
| 22 | WESTWOOD HOLDINGS GROUP INC | $24.0M | 538K | ▼−4.7% Reduced · −26K sh | Q1 2026 | |
| 23 | Praetorian PR LLC | $22.3M | 500K | —Held | Q1 2026 | |
| 24 | Bank of New York Mellon Corp | $21.6M | 485K | ▲+11% Added · +49K sh | Q1 2026 | |
| 25 | GOLDMAN SACHS GROUP INC | $21.5M | 482K | ▲+97% Added · +237K sh | 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 |
|---|---|---|---|---|---|
| Jul 13, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 12K | $761K |
| Jul 13, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 5K | $297K |
| Jul 13, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 232 | $15K |
| Jul 13, 2026 | Lowitt Ian T | Chief Executive Officer, Director | Sell (S) | 27K | $1.8M |
| Jul 13, 2026 | Lowitt Ian T | Chief Executive Officer, Director | Sell (S) | 9K | $581K |
| Jul 13, 2026 | Lowitt Ian T | Chief Executive Officer, Director | Sell (S) | 787 | $52K |
| Jun 15, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 2K | $102K |
| Jun 15, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 14K | $888K |
| Jun 15, 2026 | Tonucci Paolo | See Remarks | Sell (S) | 809 | $51K |
| Jun 12, 2026 | Lowitt Ian T | Chief Executive Officer, Director | Sell (S) | 33K | $2.0M |
| Jun 12, 2026 | Lowitt Ian T | Chief Executive Officer, Director | Sell (S) | 4K | $273K |
| Jun 9, 2026 | Assi Georges | Director | Grant (A) | 2K | $0 |
| Company | Co-held by | Combined value |
|---|---|---|
| MICROSOFT CORPMSFT | 58 funds | $21.2B |
| META PLATFORMS INC-CLASS AMETA | 58 funds | $10.1B |
| NVIDIA CORPNVDA | 57 funds | $31.3B |
| SERVICENOW INCNOW | 56 funds | $2.0B |
| UBER TECHNOLOGIES INCUBER | 56 funds | $1.8B |
| CAPITAL ONE FINANCIAL CORPCOF | 56 funds | $1.4B |
| ELI LILLY & COLLY | 55 funds | $5.4B |
| VISA INC-CLASS A SHARESV | 55 funds | $3.8B |
| BOSTON SCIENTIFIC CORPBSX | 55 funds | $1.3B |
| AMAZON.COM INCAMZN | 54 funds | $15.9B |
| ALPHABET INC-CL AGOOGL | 54 funds | $14.0B |
| BROADCOM INCAVGO | 54 funds | $12.1B |
Ranked by how many of MRX'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 MRX. 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.