Aufman Associates Inc reported 33 positions worth $77.72M for the quarter ended Jun 30, 2026, up 52.6% on the prior quarter. It opened 3 new positions, added to 5, trimmed 17 and exited 1. Its largest holding is Seagate Technology Holdings plc at 62.8% of the portfolio.
Reported 13F market value at each quarter end. A change mixes trading with price moves in the positions held.
Dollar value of shares bought and sold each quarter, at that quarter’s price. It counts trading only, not price changes.
How many positions were opened, added to, trimmed or closed each quarter.
Share of reported value in each sector at every quarter end.
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| GOOG Alphabet Inc. | +2,732 | +38.5% | $965.33K | 4.47% |
| MRNA Moderna, Inc. | +8,689 | +15.2% | $605.62K | 5.89% |
| AMD Advanced Micro Devices Inc | +730 | – | $424.06K | 0.546% |
| IBM International Business Machines Corp | +1,062 | – | $298.65K | 0.384% |
| UNH Unitedhealth Group Inc | +652 | – | $270.99K | 0.349% |
| AMZN Amazon Com Inc | +176 | +12.7% | $41.94K | 0.478% |
| DIS Walt Disney Co | +10 | +0.3% | $962.53 | 0.495% |
| AVGO Broadcom Inc. | +1 | +0.1% | $377.74 | 0.916% |
| Holding | Change | Change % | Trade Value | Weight |
|---|---|---|---|---|
| STX Seagate Technology Holdings plc | -14.9K | -22.7% | $14.37M | 62.84% |
| COP Conocophillips | -2,400 | -100.0% | $316.80K | Exited |
| BRK-B Berkshire Hathaway Inc | -620 | -9.1% | $310.24K | 3.96% |
| CCI Crown Castle Inc. | -2,000 | -14.0% | $151.46K | 1.2% |
| XOM ExxonMobil Holdings Corp | -1,090 | -12.6% | $149.03K | 1.33% |
| MTX Minerals Technologies Inc | -2,000 | -5.3% | $147.94K | 3.43% |
| AAPL Apple Inc. | -395 | -5.1% | $114.30K | 2.74% |
| RVTY Revvity, Inc. | -888 | -10.8% | $98.80K | 1.06% |
| MRK Merck & Co., Inc. | -685 | -18.6% | $88.02K | 0.494% |
| TSM Taiwan Semiconductor Manufacturing Co Ltd | -160 | -15.5% | $76.41K | 0.535% |
| Holding | Shares Sold | Trade Value | Prior Weight |
|---|---|---|---|
| COP Conocophillips | -2,400 | $316.80K | 0.622% |
| # | Activity | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 1 | STX Seagate Technology Holdings plc | Technology | 50.6K | $48.84M | 62.84% | -14.9K | -22.7% | Reduced | 0.02% |
| 2 | MRNA Moderna, Inc. | Healthcare | 65.7K | $4.58M | 5.89% | +8,689 | +15.2% | Added | 0.02% |
| 3 | GOOG Alphabet Inc. | Technology | 9,822 | $3.47M | 4.47% | +2,732 | +38.5% | Added | 0% |
| 4 | BRK-B Berkshire Hathaway Inc | Financial Services | 6,158 | $3.08M | 3.96% | -620 | -9.1% | Reduced | 0% |
| 5 | MTX Minerals Technologies Inc | Basic Materials | 36.0K | $2.66M | 3.43% | -2,000 | -5.3% | Reduced | 0.12% |
| 6 | AAPL Apple Inc. | Technology | 7,354 | $2.13M | 2.74% | -395 | -5.1% | Reduced | 0% |
| 7 | MSFT Microsoft Corp | Technology | 3,287 | $1.23M | 1.58% | -1 | 0.0% | Reduced | 0% |
| 8 | XOM ExxonMobil Holdings Corp | Energy | 7,558 | $1.03M | 1.33% | -1,090 | -12.6% | Reduced | 0% |
| 9 | CCI Crown Castle Inc. | Real Estate | 12.3K | $929.51K | 1.2% | -2,000 | -14.0% | Reduced | 0% |
| 10 | RVTY Revvity, Inc. | Healthcare | 7,372 | $820.21K | 1.06% | -888 | -10.8% | Reduced | 0.01% |
| 11 | JNJ Johnson & Johnson | Healthcare | 3,167 | $804.32K | 1.03% | -36 | -1.1% | Reduced | 0% |
| 12 | ABBV AbbVie Inc. | Healthcare | 3,196 | $804.24K | 1.03% | -66 | -2.0% | Reduced | 0% |
| 13 | AVGO Broadcom Inc. | Technology | 1,884 | $711.67K | 0.916% | +1 | +0.1% | Added | 0% |
| 14 | CVX Chevron Corp | Energy | 2,949 | $488.75K | 0.629% | -48 | -1.6% | Reduced | 0% |
| 15 | GOOGL Alphabet Inc. | Technology | 1,295 | $462.79K | 0.595% | -51 | -3.8% | Reduced | 0% |
Tip. Select a row to see that position’s full history at Aufman Associates.
As of its Q2 2026 13F filing, Aufman Associates Inc’s five largest positions were Seagate Technology Holdings plc (STX) at 62.8%, Moderna, Inc. (MRNA) at 5.9%, Alphabet Inc. (GOOG) at 4.5%, Berkshire Hathaway Inc (BRK-B) at 4.0%, Minerals Technologies Inc (MTX) at 3.4% of the reported portfolio.
Aufman Associates Inc reported a 13F portfolio worth $77.72M across 33 positions for Q2 2026. That is up 52.6% from the previous quarter.
Its largest purchases by value were Alphabet Inc. ($965.33K), Moderna, Inc. ($605.62K), Advanced Micro Devices Inc ($424.06K). It opened 3 new positions.
Its largest sales by value were Seagate Technology Holdings plc ($14.37M), Conocophillips ($316.80K), Berkshire Hathaway Inc ($310.24K). It exited 1 positions entirely.
From the Form 13F-HR reports Aufman Associates Inc files with the SEC each quarter, within 45 days of quarter end. A 13F lists long positions in US-listed equities and options; it excludes short positions, cash, bonds and most non-US holdings.
13F data reflects long positions in US-listed equities and options as reported to the SEC up to 45 days after quarter end. It excludes short positions, cash, bonds and most non-US securities, so it is not a complete picture of a manager’s assets.