75% buyers of institutions opening or closing positions this quarter
16 more new buyers than exits, ownership rose 7.65 percentage points vs the prior quarter, and 1 well-known fund manager in the top 25.
75% buyers of institutions opening or closing positions this quarter
56.7% institutional ownership
Patriot Financial Partners portfolio allocation
Institutional ownership vs Banks - Regional peers
No Form 4 insider transactions on file
Latest positioning in COSO across 13F flow, ownership shift, marquee holders, and holder-count growth.
Ranked by reported Q1 2026 13F market value
Share of total reported institutional value in COSO held by the largest 10 / 25 filers.
| # | Institution | Shares Held | Market Value | QoQ Change | Ownership % | % of Fund |
|---|---|---|---|---|---|---|
| 1 | Patriot Financial Partners GP II, L.P. | 1.2M | $28.5M | +61.2% | 9.672% | 7.34% |
| 2 | Fourthstone LLC | 1.1M | $27.1M | +14.7% | 9.182% | 4.59% |
| 3 | BlackRock, Inc. | 492K | $12.1M | +51.7% | 4.105% | 0.00% |
| 4 | VANGUARD CAPITAL MANAGEMENT LLC | 406K | $10.0M | β | 3.391% | 0.00% |
| 5 | ALLIANCEBERNSTEIN L.P. | 398K | $9.2M | -6.4% | 3.317% | 0.00% |
| 6 | Berkeley Capital Partners, LLC | 361K | $8.9M | -1.4% | 3.008% | 2.06% |
| 7 | MENDON CAPITAL ADVISORS CORP | 330K | $8.1M | +24.1% | 2.751% | 3.14% |
| 8 | North Reef Capital Management LP | 321K | $7.9M | +21.6% | 2.678% | 0.27% |
| 9 | RMB Capital Management, LLC | 303K | $7.4M | +24.4% | 2.528% | 0.13% |
| 10 | GOLDMAN SACHS GROUP INC | 258K | $6.3M | +7.8% | 2.154% | 0.00% |
| 11 | National Philanthropic Trust | 278K | $6.1M | β | 2.321% | 0.01% |
| 12 | ENDEAVOUR CAPITAL ADVISORS INC | 242K | $5.9M | -28.3% | 2.016% | 1.35% |
| 13 | EJF Capital LLC | 193K | $4.7M | -79.3% | 1.608% | 3.34% |
| 14 | GEODE CAPITAL MANAGEMENT, LLC | 191K | $4.7M | +30.0% | 1.596% | 0.00% |
| 15 | STATE STREET CORP | 126K | $3.1M | +217.0% | 1.055% | 0.00% |
| 16 | RAFFLES ASSOCIATES LP | 121K | $3.0M | 0.0% | 1.012% | 2.59% |
| 17 | KLCM Advisors, Inc. | 108K | $2.6M | 0.0% | 0.898% | 0.22% |
| 18 | TWO SIGMA INVESTMENTS, LP | 100K | $2.5M | β | 0.835% | 0.00% |
| 19 | Bleakley Financial Group, LLC | 88K | $2.2M | +0.1% | 0.735% | 0.03% |
| 20 | BANC FUNDS CO LLC | 86K | $2.1M | 0.0% | 0.715% | 0.39% |
| 21 | FIRST MANHATTAN CO | 78K | $1.9M | 0.0% | 0.648% | 0.01% |
| 22 | Elizabeth Park Capital Advisors, Ltd. | 76K | $1.9M | 0.0% | 0.632% | 1.43% |
| 23 | NORTHERN TRUST CORP | 64K | $1.6M | +45.1% | 0.538% | 0.00% |
| 24 | VANGUARD PORTFOLIO MANAGEMENT LLC | 53K | $1.3M | β | 0.446% | 0.00% |
| 25 | VANGUARD FIDUCIARY TRUST CO | 53K | $1.3M | β | 0.444% | 0.00% |
denotes a marquee investor (Buffett, Burry, ARK, Tiger Global, Pershing Square, Baupost and other widely-followed managers). β% of Fundβ shows how much of that investorβs total 13F portfolio is invested in COSO β a direct measure of their conviction.
Filings activity in COSO during Q1 2026, grouped by how each filer changed its position.
8 quarters of 13F filings Β· Ξ columns show change vs prior quarter
| Quarter | Inst. Holders | Ξ Holders | Ownership % | Ξ Ownership | Total 13F Value | Ξ Value |
|---|---|---|---|---|---|---|
| Q1 2026 | 80 | +25% | 56.73% | +7.65 pp | $183M | +16% |
| Q4 2025 | 64 | +31% | 49.08% | +7.64 pp | $159M | +18% |
| Q3 2025 | 49 | +2350% | 41.44% | +37.19 pp | $134M | +875% |
| Q2 2025 | 2 | +100% | 4.25% | +2.58 pp | $14M | +154% |
| Q1 2025 | 1 | +0.0% | 1.67% | 0.17 pp | $5M | 9.1% |
| Q4 2024 | 1 | +0.0% | 1.84% | +0.06 pp | $6M | +3.4% |
| Q3 2024 | 1 | +0.0% | 1.78% | +0.26 pp | $6M | +17% |
| Q2 2024 | 1 | β | 1.52% | β | $5M | β |
Source: SEC 13F institutional filings. Ownership % requires market cap data and will show once linked. Ξ columns compare to the immediately prior filed quarter.
No recent Form 4 insider transactions on file for COSO.
Quick answers to the most common questions about buying COSO stock.
Based on Q1 2026 13F filings, institutional ownership of CoastalSouth Bancshares, Inc. stands at 56.7%, held across 80 reporting institutions.
Patriot Financial Partners GP II, L.P. is the largest reported institutional holder of COSO, with approximately 1,159,211 shares worth $0.03B as of Q1 2026.
Yes β 1 widely-followed marquee investor appear among the top 25 institutional holders of COSO, including TWO SIGMA INVESTMENTS, LP.
Our composite Smart Money Score for COSO is 67 out of 100 (Bullish). It combines net institutional buying activity, ownership shift, marquee investor presence, and holder-count growth.
24 institutions opened new positions in COSO during Q1 2026, while 8 fully exited. 47 added to existing positions and 9 trimmed.
COSO institutional ownership rose by 7.65 percentage points quarter-over-quarter, with a net change of +16 holders.
The top 10 institutions account for 68.5% of all reported 13F value in COSO, and the top 25 account for 93.0%.
All data is sourced from SEC Form 13F filings, which institutional investment managers with at least $100M in assets are required to file each quarter. We process every 13F filing from EDGAR and recompute the aggregates after each cycle. Insider transactions are sourced from Form 4 filings.