O'Connor Alternative Investments LLC
PERIOD 2026-Q1 (filed 2026-05-15) · SOURCE: SEC EDGAR (PUBLIC)
Holdings as of the 2026-Q1 13F-HR filing (filed 2026-05-15). 13F is disclosed up to 45 days after quarter-end.
What a 13F does — and does not — show
These figures come from Form 13F, a quarterly filing that large US institutional managers must submit to the SEC. It is a useful window, but a partial and lagged one, so read it carefully:
- It is a snapshot, up to 45 days old. A 13F shows what a manager held on the last day of a quarter, filed up to 45 days later — the fund may have traded since.
- Long US-listed stocks only. It excludes short positions, cash, bonds, most derivatives, and non-US or private holdings, so it is not the fund’s whole portfolio.
- Reported 13F value is not assets under management. Every share and concentration figure below is a percentage of the reported 13F value only — not the firm’s total assets.
- It describes, it does not recommend. A large or long-held position is not an endorsement, and none of this is investment advice.
Concentration
Share of reported portfolio value. Long US-listed equity positions as filed; percentages are of reported 13F value, which excludes shorts, cash, non-US and private holdings.
| Tier | Reported value | Share |
|---|---|---|
| Top position | $236M | 23.1% |
| Top 5 | $713M | 69.7% |
| Top 10 | $818M | 80.0% |
Top holdings
| # | Security | Shares | Reported value | % of value |
|---|---|---|---|---|
| 1 | HOLX HOLOGIC IN | 3,118,178 | $236M | 23.1% |
| 2 | AL AIR LEASE | 2,860,079 | $186M | 18.2% |
| 3 | FOLD AMICUS THE | 8,444,992 | $122M | 11.9% |
| 4 | SDA SEALED AIR | 2,214,582 | $93M | 9.1% |
| 5 | OS ONESTREAM | 3,186,804 | $76M | 7.5% |
| 6 | DAWN DAY ONE BI | 1,867,553 | $40M | 3.9% |
| 7 | CARNIVAL P | 982,643 | $25M | 2.5% |
| 8 | KLAC KLARNA GRO | 1,127,170 | $15M | 1.4% |
| 9 | GOOGL ALPHABET I | 50,250 | $14M | 1.4% |
| 10 | SMH VANECK ETF | 27,500 | $11M | 1.0% |
| 11 | RNA ATRIUM THE | 578,011 | $8M | 0.8% |
| 12 | FOX FOX CORP | 137,780 | $7M | 0.7% |
Sector mix
Reported 13F value by sector, as a share of the largest positions we rank. Sectors come from company reference data joined to each holding. 17% of this value is not classified to a sector and is excluded from the mix. Long US-listed equity positions as filed.
| Sector | Reported value | Share |
|---|---|---|
| Healthcare | $398M | 45.5% |
| Industrials | $186M | 21.3% |
| Technology | $91M | 10.4% |
| Communication Services | $26M | 3.0% |
| Financial Services | $24M | 2.7% |
How this filer invests
Reproducible measures computed from the positions in this filer’s own 13F filings — not from any outside estimate.
How concentrated the book is
Across 115 reported positions. Shares are of reported 13F value (long US-listed equity), which is not the firm’s total assets. The concentration index (HHI) is the sum of each position’s squared weight — higher means a book concentrated in fewer names.
Frequently asked
What does O'Connor Alternative Investments LLC own?
O'Connor Alternative Investments LLC reported 110 long US-listed equity positions worth $1.0B in its 2026-Q1 13F filing.
Where does this data come from?
Holdings are parsed from SEC Form 13F-HR filings on EDGAR (public filings). 13F is disclosed up to 45 days after quarter-end and reflects long US-listed equity positions only. Informational, not investment advice.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It is filed up to 45 days after quarter-end, so it is backward-looking — the manager may have traded since — and it covers long US-listed equities only, not short positions, cash, or private holdings. Reading a 13F tells you what a manager owned, not whether you should own it.