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 MACI 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/MACI"
Use Arkolith to show who owns MACI, which funds added or reduced it, and which SEC filings prove each claim.
| # | Fund | Position value | Shares | Last move | As of | History |
|---|---|---|---|---|---|---|
| 1 | LMR Partners LLP | $16.0M | 1.5M | —Held | Q1 2026 | |
| 2 | Polar Asset Management Partners Inc. | $16.0M | 1.5M | —Held | Q1 2026 | |
| 3 | First Trust Capital Management L.P. | $15.1M | 1.4M | —Held | Q1 2026 | |
| 4 | AQR Arbitrage LLC | $10.8M | 996K | ▼−0.1% Reduced · −680 sh | Q1 2026 | |
| 5 | Karpus Management, Inc. | $10.6M | 989K | ▼−14% Reduced · −157K sh | Q1 2026 | |
| 6 | Westchester Capital Management, LLC | $4.6M | 425K | —Held | Q1 2026 | |
| 7 | Magnetar Financial LLC | $4.0M | 371K | —Held | Q1 2026 | |
| 8 | Hudson Bay Capital Management LP | $3.5M | 325K | —Held | Q1 2026 | |
| 9 | Alberta Investment Management Corp | $3.5M | 325K | —Held | Q1 2026 | |
| 10 | PICTON MAHONEY ASSET MANAGEMENT | $3.5M | 325K | —Held | Q1 2026 | |
| 11 | RIVERNORTH CAPITAL MANAGEMENT, LLC | $3.2M | 299K | —Held | Q1 2026 | |
| 12 | HIGHBRIDGE CAPITAL MANAGEMENT LLC | $3.1M | 289K | ▲New +289K sh | Q1 2026 | |
| 13 | MOORE CAPITAL MANAGEMENT, LP | $808K | 75K | —Held | Q1 2026 | |
| 14 | Dakota Wealth Management | $404K | 38K | —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 11, 2026 | Melar Acquisition Sponsor I LLC | 10% Owner | Conversion (C) | 5.6M | — |
| Jun 11, 2026 | Melar Acquisition Sponsor I LLC | 10% Owner | Conversion (C) | 5.6M | $0 |
| Company | Co-held by | Combined value |
|---|---|---|
| ANDRETTI ACQUISITION CORP -APOLE | 13 funds | $119.3M |
| K&F GROWTH ACQUISITION COR-AKFII | 13 funds | $111.5M |
| LEGATO MERGER CORP IIILEGT | 13 funds | $105.9M |
| OYSTER ENTERPRISES II ACQ-AOYSE | 13 funds | $92.8M |
| SOULPOWER ACQUISITION CO-ASOUL | 13 funds | $90.8M |
| TRANSLATIONAL DEVELOPMENT ACTDAC | 13 funds | $77.3M |
| CAL REDWOOD ACQUISIT-CL ACRAQ | 13 funds | $65.3M |
| PLUM ACQUISITION CORP IVPLMK | 13 funds | $60.2M |
| GP-ACT III ACQUISITION-AGPAT | 12 funds | $143.3M |
| DRUGS MADE IN AMERICA ACQUISDMII | 12 funds | $135.9M |
| LIONHEART HOLDINGS - CL ACUB | 12 funds | $132.8M |
| GRAF GLOBAL CORP-CL AGRAF | 12 funds | $117.1M |
Ranked by how many of MACI'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 MACI. 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.