Institutional Manager · CIK 0001585047
Columbia Asset Management
Ann Arbor, MI · File #028-15791
Latest AUM
$562.7M
Positions
174
Top-10 Concentration
52.0%
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 |
|---|---|---|---|---|---|
| NEW | BERKSHIRE HATHAWAY INC DEL | BRK-A | +37,270 | +$18.7M | $0 |
| ADD | NETFLIX INC | NFLX | +29,266 | +$2.7M | -$3.7M |
| REDUCE | BROADCOM INC | AVGO | -5,746 | -$2.0M | +$880,076 |
| NEW | UNILEVER PLC | UNLYF | +16,933 | +$1.1M | $0 |
| EXITED | UNILEVER PLC | 904767704 | -18,455 | -$1.1M | $0 |
| REDUCE | ALPHABET INC | GOOG | -3,399 | -$1.1M | +$5.6M |
| ADD | VANGUARD INDEX FDS | 922908629 | +3,508 | +$1.0M | -$25,947 |
| REDUCE | APPLE INC | AAPL | -3,704 | -$1.0M | +$3.5M |
| REDUCE | MICROSOFT CORP | MSFT | -1,766 | -$854,076 | -$3.2M |
| ADD | VERTEX PHARMACEUTICALS INC | VRTX | +1,690 | +$766,178 | +$34,131 |
Sector Allocation
Filing History
- 13F HOLDINGS REPORTQ/E Dec 2025174 pos · $562.7M
- 13F HOLDINGS REPORTQ/E Sep 2025168 pos · $534.4M
- 13F HOLDINGS REPORTQ/E Jun 2025170 pos · $508.8M
- 13F HOLDINGS REPORTQ/E Mar 2025232 pos · $511.2M
- 13F HOLDINGS REPORTQ/E Dec 2024268 pos · $547.1M
- 13F HOLDINGS REPORTQ/E Sep 2024181 pos · $573,766
- 13F HOLDINGS REPORTQ/E Jun 2024172 pos · $536,410
- 13F HOLDINGS REPORTQ/E Mar 2024168 pos · $493,201
- 13F HOLDINGS REPORTQ/E Dec 2023166 pos · $452,924
Top 20 Holdings — Dec 2025
| # | Issuer | Ticker | Shares | Value | % of Portfolio |
|---|---|---|---|---|---|
| 1 | APPLE INC | AAPL | 199,639 | $54.3M | 11.79% |
| 2 | MICROSOFT CORP | MSFT | 90,169 | $43.6M | 9.48% |
| 3 | ALPHABET INC | GOOG | 77,166 | $24.2M | 5.25% |
| 4 | ERIE INDTY CO | 29530P102 | 71,748 | $20.6M | 4.47% |
| 5 | AMAZON COM INC | AMZN | 84,341 | $19.5M | 4.23% |
| 6 | BERKSHIRE HATHAWAY INC DEL | BRK-A | 37,270 | $18.7M | 4.07% |
| 7 | VISA INC | V | 51,807 | $18.2M | 3.95% |
| 8 | BROADCOM INC | AVGO | 48,605 | $16.8M | 3.66% |
| 9 | MERCK & CO INC | MRK | 111,534 | $11.7M | 2.55% |
| 10 | JOHNSON & JOHNSON | JNJ | 56,069 | $11.6M | 2.52% |
| 11 | ALPHABET INC | GOOG | 35,811 | $11.2M | 2.44% |
| 12 | JPMORGAN CHASE & CO. | VYLD | 33,662 | $10.8M | 2.36% |
| 13 | INTERNATIONAL BUSINESS MACHS | INTR | 32,471 | $9.6M | 2.09% |
| 14 | SPDR S&P 500 ETF TR | SPY | 13,892 | $9.5M | 2.06% |
| 15 | ELI LILLY & CO | LLY | 8,346 | $9.0M | 1.95% |
| 16 | CATERPILLAR INC | CAT | 15,083 | $8.6M | 1.88% |
| 17 | ABBVIE INC | ABBV | 35,484 | $8.1M | 1.76% |
| 18 | AMGEN INC | AMGN | 23,003 | $7.5M | 1.64% |
| 19 | CISCO SYS INC | CSCO | 97,003 | $7.5M | 1.62% |
| 20 | STARBUCKS CORP | SBUX | 84,261 | $7.1M | 1.54% |