Atrium Therapeutics (RNA) Held by Superinvestors
ATRIUM THERAPEUTICS INC (RNA) is currently held by 2 superinvestors tracked by InsiderSet, with a combined reported market value of approximately $3.72M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Arbiter Partners Capital Management is currently the largest disclosed institutional shareholder of RNA tracked by InsiderSet, reporting ownership valued at approximately $3.51M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $2.14M, representing an estimated loss of -39.03% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 100% of the total disclosed RNA value among the investors covered in this analysis. Major shareholders include Arbiter Partners Capital Management, Renaissance Technologies LLC, and several other long-term asset managers with concentrated positions in ATRIUM THERAPEUTICS INC (RNA).
This page ranks the largest institutional RNA shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Arbiter Partners Capital Management | Paul Isaac | 1.88% | 261,288 | $3,514,324 | $2,142,562 | -$1,371,762 | -39.03% |
| Renaissance Technologies LLC | Jim Simons | 0.00% | 14,971 | $201,360 | $122,762 | -$78,598 | -39.03% |
Frequently asked questions about RNA
Who are the largest superinvestors holding RNA?
The largest superinvestors holding RNA in the latest SEC Form 13F filings include Arbiter Partners Capital Management and Renaissance Technologies LLC. InsiderSet ranks these superinvestors by their latest reported RNA position.
What does the RNA superinvestors page include?
This page tracks RNA positions reported by a curated group of notable institutional investors and fund managers through SEC Form 13F. ATRIUM THERAPEUTICS INC (RNA) on this page reflects disclosed 13F holdings among those superinvestors, not every institutional shareholder of the stock.
How many superinvestors hold RNA?
InsiderSet currently tracks 2 superinvestors reporting RNA holdings in the latest available 13F data. This is the curated set on this page, not the total number of institutions that own RNA.
How much RNA stock do superinvestors hold?
Superinvestors tracked by InsiderSet disclosed approximately $3.72M in RNA holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value, and it covers the curated superinvestors on this page rather than every institutional filer.
When were RNA superinvestor holdings last updated?
The latest RNA superinvestor holdings on InsiderSet are based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time holdings.
Are superinvestor RNA holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by these superinvestors as of the end of the reporting quarter. A superinvestor may have changed its RNA position after the reporting date.
Are superinvestors buying or selling RNA?
Buying and selling can be analyzed by comparing RNA positions across consecutive 13F reporting periods. InsiderSet's RNA Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View RNA ownership changes.
How have superinvestor RNA holdings changed over time?
InsiderSet tracks RNA holdings among these superinvestors across multiple 13F reporting periods, so holder counts, reported value, and reported shares can be compared over time.