Institutional Manager · CIK 0001008877
WOODSTOCK CORP
BOSTON, MA · File #028-05258
Latest AUM
$1.17B
Positions
156
Top-10 Concentration
49.5%
Filings
9
Portfolio Value Over Time
2024-03
2024-06
2024-09
2024-12
2025-03
2025-06
2025-09
2025-12
Biggest QoQ Changes
Ranked by conviction flow (share change × current price) so mark-to-market moves don't dominate. Price effect column shows how much of the $ change was just the stock moving.
| Action | Issuer | Ticker / CUSIP | Δ Shares | Flow ($) | Price Effect |
|---|---|---|---|---|---|
| REDUCE | NVIDIA Corp | NVDA | -11,964 | -$2.2M | -$47,309 |
| ADD | Regeneron Pharmaceuticals | REGN | +2,036 | +$1.6M | +$3.5M |
| REDUCE | United Parcel Service Inc CL B | UPS | -7,211 | -$715,259 | +$664,485 |
| REDUCE | Omniab Inc | OABIW | -316,513 | -$585,549 | +$87,938 |
| EXITED | Ultragenyx Pharmaceutical Inc | 90400D108 | -18,114 | -$544,869 | $0 |
| ADD | Sherwin Williams Co | SHW | +1,454 | +$471,140 | -$139,538 |
| NEW | Poet Technologies Inc New | POET | +67,900 | +$429,807 | $0 |
| REDUCE | Fortinet Inc | FTNT | -4,729 | -$375,530 | -$1.2M |
| REDUCE | Hershey Co | HSY | -2,045 | -$372,143 | -$105,709 |
| ADD | Select Sector SPDR Tr Technolo | 81369Y803 | +2,500 | +$359,925 | -$344,725 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 2025156 pos · $1.17B
- 13F HOLDINGS REPORTQ/E Sep 2025157 pos · $1.15B
- 13F HOLDINGS REPORTQ/E Jun 2025156 pos · $1.09B
- 13F HOLDINGS REPORTQ/E Mar 2025153 pos · $1.01B
- 13F HOLDINGS REPORTQ/E Dec 2024156 pos · $1.04B
- 13F HOLDINGS REPORTQ/E Sep 2024165 pos · $1.04B
- 13F HOLDINGS REPORTQ/E Jun 2024165 pos · $983.4M
- 13F HOLDINGS REPORTQ/E Mar 2024165 pos · $966.0M
- 13F HOLDINGS REPORTQ/E Dec 2023168 pos · $797.5M
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | NVIDIA Corp | NVDA | 579,400 | $108.1M | 11.03% |
| 2 | Microsoft Corp | MSFT | 158,410 | $76.6M | 7.82% |
| 3 | O'Reilly Automotive Inc | 67103H107 | 558,211 | $50.9M | 5.20% |
| 4 | Alphabet Inc Class C | GOOG | 160,620 | $50.4M | 5.15% |
| 5 | Intuitive Surgical Inc | ISRG | 82,309 | $46.6M | 4.76% |
| 6 | Apple Inc | AAPL | 168,718 | $45.9M | 4.68% |
| 7 | Alphabet Inc Class A | GOOG | 113,325 | $35.5M | 3.62% |
| 8 | Rtx Corporation Com | RTX | 148,844 | $27.3M | 2.79% |
| 9 | JPMorgan Chase & Co | VYLD | 68,892 | $22.2M | 2.27% |
| 10 | Oracle Corp | ORCL-PD | 109,622 | $21.4M | 2.18% |
| 11 | Abbvie Inc | ABBV | 93,134 | $21.3M | 2.17% |
| 12 | Home Depot Inc | HD | 60,274 | $20.7M | 2.12% |
| 13 | Fortinet Inc | FTNT | 253,367 | $20.1M | 2.05% |
| 14 | Costco Wholesale Corp | 22160K105 | 22,165 | $19.1M | 1.95% |
| 15 | Abbott Laboratories | ABLZF | 135,524 | $17.0M | 1.73% |
| 16 | Johnson & Johnson | JNJ | 80,804 | $16.7M | 1.71% |
| 17 | Idexx Laboratories Inc | 45168D104 | 24,168 | $16.4M | 1.67% |
| 18 | Wal-Mart Stores Inc | WMT | 142,942 | $15.9M | 1.63% |
| 19 | iShares Russell Mid-Cap ETF | 464287499 | 163,334 | $15.7M | 1.61% |
| 20 | Automatic Data Processing Inc | ADP | 56,128 | $14.4M | 1.47% |