JANA Partners
Barry Rosenstein · CIK 0001159159 · latest 13F for 2026-06-30 filed 2026-08-14
Estimated from 13F holdings — long US equities only; follow-the-filing returns are net of an assumed 10 bps per unit of turnover.
About the fund
JANA Partners is an investment management firm founded in 2001 by Barry Rosenstein. The firm specializes in event-driven and activist investing, focusing on shareholder engagement to unlock value in undervalued public companies.
Strategy
Value-oriented, event-driven, and activist shareholder engagement.
Investment approach
JANA employs a value-oriented, event-driven strategy centered on active shareholder engagement. The firm conducts fundamental research to identify undervalued public companies with specific catalysts for value creation. It seeks to work constructively with management to effect change or, if necessary, pursues a shareholder activist strategy to unlock value. The firm emphasizes a disciplined approach, often referred to as V cubed, and aims to mitigate risk through due diligence and position limits.
History
JANA Partners was founded in 2001 by Barry Rosenstein. The firm has established itself as an engaged investor, focusing on shareholder activism to create value in public companies. Over its history, the firm has managed various investment vehicles and has been involved in notable activist campaigns with companies such as Apple, Whole Foods, and Tiffany's.
Notable positions & campaigns
- Apple — Activist engagement with the company.
- Whole Foods — Activist engagement with the company.
- Tiffany's — Activist engagement with the company.
Profile generated 2026-10-09 from public sources; may be incomplete or out of date.
- Founded by
- Barry Rosenstein
- Founded
- 2001
- HQ
- New York, United States
- Reported AUM
- $2.3bn (as of 2026-03-27)
- Website
- janapartners.com
Management
- Barry RosensteinManaging Partner and Co-Portfolio Manager
- Jennifer FanjiangPartner, Chief Legal Officer and Chief Compliance Officer
Holdings heatmap
Latest 13F (2026-06-30): top 10 positions grouped by sector, sized by weight, coloured by the change in weight since the previous 13F.
Holdings map
Each tile is a position, sized by reported value and coloured by the stock's own price return (red down, green up) — the LiquidRound / finviz-style map.
Copy portfolio vs SPY
Growth of $1 following each filing the trading day after it was filed.
Top holdings
Latest 13F (2026-06-30).
| # | Ticker | Value | Weight |
|---|---|---|---|
| 1 | MRCY | $484M | 25.5% |
| 2 | COO | $257M | 13.5% |
| 3 | SPY | $256M | 13.5% |
| 4 | LW | $233M | 12.2% |
| 5 | FISV | $180M | 9.4% |
| 6 | MKL | $150M | 7.9% |
| 7 | ALKT | $122M | 6.4% |
| 8 | FUN | $88M | 4.6% |
| 9 | P | $78M | 4.1% |
| 10 | RPD | $55M | 2.9% |
Sector mix
Top-25 holdings by weight.
Changes this quarter
| Move | Ticker | Prev wt | Now wt |
|---|---|---|---|
| trimmed | FISV | 14.8% | 9.4% |
| exited | — | 1.8% | 0.0% |
| added | ALKT | 5.1% | 6.4% |
| added | LW | 12.7% | 12.2% |
| trimmed | P | 3.7% | 4.1% |
Quarterly copy returns
Each 13F held from the day after filing until the next filing.
| 13F period | Copy | SPY | Alpha | Coverage |
|---|---|---|---|---|
| 2026-06-30 | -13.7% | +0.4% | -14.1% | 100% |
| 2026-03-31 | +12.1% | +4.9% | +7.2% | 98% |
| 2025-12-31 | -4.4% | +7.9% | -12.4% | 92% |
| 2025-09-30 | +4.6% | +3.4% | +1.2% | 93% |
| 2025-06-30 | -1.3% | +3.7% | -5.0% | 93% |
| 2025-03-31 | +9.9% | +8.6% | +1.3% | 92% |
| 2024-12-31 | -3.8% | -2.5% | -1.3% | 88% |
| 2024-09-30 | -2.9% | +4.7% | -7.6% | 76% |
| 2024-06-30 | +9.3% | +6.2% | +3.1% | 66% |
| 2024-03-31 | +6.2% | +4.9% | +1.3% | 68% |
| 2023-12-31 | +14.3% | +5.6% | +8.7% | 71% |
| 2023-09-30 | +13.9% | +12.1% | +1.8% | 53% |
| 2023-06-30 | -5.2% | +1.9% | -7.1% | 57% |
| 2023-03-31 | +10.1% | +8.4% | +1.8% | 49% |
| 2022-12-31 | -12.9% | -0.5% | -12.4% | 49% |
| 2022-09-30 | +5.0% | +4.4% | +0.7% | 46% |
Filing dates
- 2026-08-1413F-HR for 2026-06-30 · $1.9B · 10 rows
- 2026-06-3013F-HR/A for 2026-03-31 · $62M · 1 rows
- 2026-05-1513F-HR for 2026-03-31 · $1.6B · 10 rows
- 2026-02-1713F-HR for 2025-12-31 · $1.9B · 12 rows
- 2025-11-1413F-HR for 2025-09-30 · $2.1B · 12 rows
- 2025-08-1413F-HR for 2025-06-30 · $2.0B · 10 rows
- 2025-05-1513F-HR for 2025-03-31 · $1.9B · 10 rows
- 2025-02-1413F-HR for 2024-12-31 · $2.0B · 11 rows
- 2024-11-1413F-HR for 2024-09-30 · $1.9B · 12 rows
- 2024-08-1413F-HR for 2024-06-30 · $1.7B · 12 rows
- 2024-05-1513F-HR for 2024-03-31 · $1.8B · 10 rows
- 2024-02-1413F-HR for 2023-12-31 · $1.5B · 8 rows
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