RUBI · Rubico Inc. · Holdings
Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.
Institutional Ownership Trend
Holder Concentration
Across 3 13F filers · Δ vs Mar 31, 2026Who Holds RUBI
Last 4 quarters through Jun 30, 2026Each kind of 13F filer's share of the common shares 13F filers report. Holder type comes from regulatory records, never the filer's name; style, turnover and horizon are measured from each filer's own 13F book. The quarter selector does not change this card.
Jun 30, 2026: 3 filers, like-for-like change +23058.9%; actively managed books +23058.9%.
| Holder type | Share | Filers | Change |
|---|---|---|---|
| Registered adviser | 78.4% | 1 | new |
| Bank | 21.6% | 2 | +47723.1% |
| Non-US | 0.0% | 0 | — |
| Unknown | 0.0% | 0 | -100.0% |
| Style | Share | Filers | Change |
|---|---|---|---|
| Systematic-like | 0.0% | 0 | -100.0% |
| Concentrated | 78.4% | 1 | new |
| Diversified active | 21.6% | 2 | +6117.0% |
| Unknown | 0.0% | 0 | — |
| Turnover | Share | Filers | Change |
|---|---|---|---|
| Low turnover | 0.2% | 1 | new |
| Medium turnover | 99.8% | 2 | +220350.0% |
| High turnover | 0.0% | 0 | -100.0% |
| Unknown | 0.0% | 0 | — |
| Holding horizon | Share | Filers | Change |
|---|---|---|---|
| Short horizon | 78.4% | 1 | new |
| Medium horizon | 0.0% | 0 | — |
| Long horizon | 21.6% | 2 | +4913.7% |
| Unknown | 0.0% | 0 | — |
| 13F book size | Share | Filers | Change |
|---|---|---|---|
| $1B to $10B | 78.4% | 1 | +93650.0% |
| $100B or more | 21.6% | 2 | +6117.0% |
| Under $1B | 0.0% | 0 | — |
| $10B to $100B | 0.0% | 0 | — |
| Client base | Share | Filers | Change |
|---|---|---|---|
| Pooled investment vehicles | 78.4% | 1 | new |
| Individuals and high net worth | 0.0% | 0 | — |
| Unknown | 21.6% | 2 | +4913.7% |
| Private funds | Share | Filers | Change |
|---|---|---|---|
| Hedge funds | 78.4% | 1 | new |
| No private funds | 0.0% | 0 | — |
| Unknown | 21.6% | 2 | +4913.7% |
| Location | Share | Filers | Change |
|---|---|---|---|
| United States | 78.4% | 1 | +20170.3% |
| Outside the US | 21.6% | 2 | +47723.1% |
How the mix is measured
Shares are 13F common shares restated to today's split basis; options and principal amounts are left out. The change compares only filers with a 13F in both quarters and keeps each filer in its bucket of the later quarter on both sides; a filer that continues under a new CIK is compared through its successor. Holder type comes from each filer's current regulatory profile; client base and private funds come from the Form ADV roster current at each quarter end (rosters from December 2019, so an earlier quarter reads Unknown). Style, turnover, horizon and book size are measured from each filer's 13F book in the newest measured quarter, and Not measured means none was. Actively managed books are those measured systematic-like, concentrated or diversified active.
Conviction and Crowding
3 13F filers, quarter ended Jun 30, 2026Measured across every 13F filer's common-share book once the quarter's filing window closed. Crowding counts filers with high turnover or that advise private funds on Form ADV.
Managers in the top fifth by current three-year FundScore alpha were net buyers of $0 (0 buying, 0 selling).
Shareholder Targets
13F filers that own its peers but not RUBI, quarter ended Jun 30, 2026RUBI has no holder-overlap peers, so these filers hold the largest Industrials stocks: SPCX, CAT, GE, GEV, RTX, UNP, ETN, BA, DE, PH, VRT, HWM, PWR, TT, LMT, CMI, GD, JCI, WM, TDG. 6,184 filers in all.
| # | Filer | In peers | Largest peers |
|---|---|---|---|
| 1 | BlackRock, Inc. Holding company, Index-like | $280,724,749,987 20 held | CAT, GE, GEV |
| 2 | VANGUARD CAPITAL MANAGEMENT LLC Registered adviser, Index-like | $215,824,179,015 20 held | CAT, GE, GEV |
| 3 | STATE STREET CORP Bank, Index-like | $184,911,734,750 20 held | CAT, RTX, GE |
| 4 | FMR LLC Holding company, Diversified active | $144,746,930,054 20 held | SPCX, GEV, GE |
| 5 | Alphabet Inc. Unknown, Concentrated | $94,176,237,970 1 held | SPCX |
| 6 | Valor Management LLC Adviser, Concentrated | $86,013,406,595 1 held | SPCX |
| 7 | VANGUARD PORTFOLIO MANAGEMENT LLC Registered adviser, Diversified active | $83,375,688,063 20 held | CAT, GE, VRT |
| 8 | GEODE CAPITAL MANAGEMENT, LLC Registered adviser, Index-like | $79,403,501,999 20 held | CAT, GE, GEV |
| 9 | JPMORGAN CHASE & CO Bank, Diversified active | $74,141,867,585 20 held | CAT, GEV, ETN |
| 10 | MORGAN STANLEY Holding company, Index-like | $64,936,309,317 20 held | CAT, GEV, RTX |
Quarterly Activity
New and Sold Out count only filers that reported a 13F for both quarters: a first-time filer's book is not a buy, and a fund that has not filed, or withheld its positions under confidential treatment, has not sold.
Top Buyers
vs Mar 31, 2026| Institution | Added | Now Holds | Open |
|---|---|---|---|
| Mega UBS Group AG | +12,290 | 12,316 |
Top Sellers
vs Mar 31, 2026Top New Positions
vs Mar 31, 2026| Institution | Acquired | Value (USD) | Open |
|---|---|---|---|
| Mid Cable Car Capital, LP | 45,000 | $162,900 | |
| Mega ROYAL BANK OF CANADA | 117 | $423 |
Top Sold-Out Positions
vs Mar 31, 2026| Institution | Previously Held | Last Value (USD) | Open |
|---|---|---|---|
| Mega JANE STREET GROUP, LLC | 174 | $13,848 | |
| Mid Tower Research Capital LLC (TRC) | 48 | $3,853 | |
| Mega CITIGROUP INC | 0 | $14 | |
| Mid SBI Securities Co., Ltd. | 0 | $0 |
| Holder | Value (USD) | % of 13F | Shares | Type | Filed | Open |
|---|---|---|---|---|---|---|
| Mid Cable Car Capital, LP Registered adviser | $162,900 | 78.35% | 30,000 | Shares | 2026-08-14 | |
| Mega UBS Group AG Bank | $44,585 | 21.44% | 8,211 | Shares | 2026-08-13 | |
| Mega ROYAL BANK OF CANADA Bank | $423 | 0.20% | 78 | Shares | 2026-08-14 |