Old Second Bancorp, Inc. (OSBC) Ownership
OSBC ownership summary
as of October 18, 2026- Institutions
- 79.1% of shares outstanding
- Insiders
- 4.33% of shares outstanding
- Shares outstanding
- 50.9M
- Float
- 49.2M shares available to trade
- Short interest
- 5.60% 2.7M shares short
- Days to cover
- 5.73 short interest up 11.2% vs prior month
- Institutions 79.11%
- Insiders 4.33%
- Other investors 16.56%
OSBC top institutional holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | BlackRock Inc | 8.45% | 4.3M | $107.0M | +172,439 (+4.2%) | June 30, 2026 |
| 2 | Dimensional Fund Advisors, Inc. | 4.91% | 2.5M | $62.2M | +109,809 (+4.6%) | June 30, 2026 |
| 3 | Vanguard Capital Management, LLC | 4.28% | 2.2M | $54.2M | −71,972 (−3.2%) | June 30, 2026 |
| 4 | State Street Corp | 3.62% | 1.8M | $45.8M | +239,900 (+15.0%) | June 30, 2026 |
| 5 | Davis Asset Management, L.P. | 3.54% | 1.8M | $44.8M | — | June 30, 2026 |
| 6 | American Century Companies Inc | 3.51% | 1.8M | $44.4M | +192,877 (+12.1%) | June 30, 2026 |
| 7 | The Goldman Sachs Group Inc | 3.19% | 1.6M | $40.4M | −66,671 (−3.9%) | June 30, 2026 |
| 8 | FJ Capital Management LLC | 2.87% | 1.5M | $36.3M | −44,689 (−3.0%) | June 30, 2026 |
| 9 | Boston Partners Global Investors, Inc | 2.78% | 1.4M | $35.2M | −28,724 (−2.0%) | June 30, 2026 |
| 10 | Geode Capital Management, LLC | 2.65% | 1.3M | $33.6M | +67,421 (+5.3%) | June 30, 2026 |
| 11 | Kennedy Capital Management Inc | 2.43% | 1.2M | $30.8M | −31,507 (−2.5%) | June 30, 2026 |
| 12 | Banc Funds Co LLC | 2.03% | 1.0M | $25.7M | +5,000 (+0.5%) | June 30, 2026 |
| 13 | Manufacturers Life Insurance Co | 1.72% | 873K | $21.7M | −6,019 (−0.7%) | June 30, 2026 |
| 14 | Vanguard Portfolio Management, LLC | 1.61% | 819K | $20.4M | +106,935 (+15.0%) | June 30, 2026 |
| 15 | Stieven Capital Advisors, L.p. | 1.60% | 815K | $20.3M | +41,800 (+5.4%) | June 30, 2026 |
| 16 | River Street Advisors LLC | 1.53% | 779K | $19.4M | +32,348 (+4.3%) | June 30, 2026 |
| 17 | AllianceBernstein L.P. | 1.26% | 642K | $16.0M | −49,000 (−7.1%) | June 30, 2026 |
| 18 | JPMorgan Chase & Co | 1.09% | 556K | $13.8M | −145,351 (−20.7%) | June 30, 2026 |
| 19 | Northern Trust Corp | 1.09% | 555K | $13.8M | −208,933 (−27.3%) | June 30, 2026 |
| 20 | Wellington Management Company LLP | 1.07% | 544K | $13.5M | −313,440 (−36.5%) | June 30, 2026 |
Value at the latest close. Change = shares bought or sold in the latest quarterly filing (13F). In the top 20, 9 holders added 969K shares and 10 cut 966K.
OSBC top mutual fund and ETF holders
20 largest| # | Holder | % of shares | Shares | Value | Change | Reported |
|---|---|---|---|---|---|---|
| 1 | Avantis US Small Cap Value ETF | 3.19% | 1.6M | $40.3M | +1,296 (+0.1%) | September 30, 2026 |
| 2 | Vanguard MStar Total Stk Mkt Idx Invest | 3.05% | 1.6M | $38.7M | — | August 31, 2026 |
| 3 | iShares Russell 2000 ETF | 2.67% | 1.4M | $33.8M | +31,526 (+2.4%) | September 30, 2026 |
| 4 | Fidelity Small Cap Index | 1.08% | 549K | $13.7M | +3,370 (+0.6%) | July 31, 2026 |
| 5 | State Street® SPDR® S&PRgnllBkgETF | 1.00% | 511K | $12.7M | +15,264 (+3.1%) | September 30, 2026 |
| 6 | JHancock Regional Bank A | 0.89% | 451K | $11.2M | — | August 31, 2026 |
| 7 | iShares Russell 2000 Value ETF | 0.88% | 445K | $11.1M | +676 (+0.2%) | September 30, 2026 |
| 8 | Goldman Sachs Small Cap Value A | 0.85% | 434K | $10.8M | +181 (+0.0%) | June 30, 2026 |
| 9 | DFA US Small Cap Value I | 0.81% | 412K | $10.3M | +45,707 (+12.5%) | August 31, 2026 |
| 10 | Vanguard Strategic Small-Cap Equity Inv | 0.72% | 368K | $9.2M | +59,501 (+19.3%) | June 30, 2026 |
| 11 | JH Financial Opportunities | 0.70% | 356K | $8.9M | — | August 31, 2026 |
| 12 | DFA US Targeted Value I | 0.61% | 312K | $7.8M | — | August 31, 2026 |
| 13 | Boston Partners Small Cap Value II Inv | 0.60% | 303K | $7.5M | −14,424 (−4.5%) | July 31, 2026 |
| 14 | Vanguard Russell 2000 ETF | 0.58% | 295K | $7.3M | +3,129 (+1.1%) | September 30, 2026 |
| 15 | Dimensional US Targeted Value ETF | 0.55% | 282K | $7.0M | — | September 30, 2026 |
| 16 | Dimensional US Small Cap Value ETF | 0.54% | 273K | $6.8M | — | September 24, 2026 |
| 17 | Schwab US Small-Cap ETF™ | 0.53% | 269K | $6.7M | +180 (+0.1%) | September 30, 2026 |
| 18 | EA Bridgeway Omni Small-Cap Value ETF | 0.50% | 255K | $6.3M | −3,552 (−1.4%) | September 30, 2026 |
| 19 | Fidelity Extended Market Index | 0.48% | 245K | $6.1M | −8,920 (−3.5%) | August 31, 2026 |
| 20 | DFA US Small Cap I | 0.45% | 230K | $5.7M | — | August 31, 2026 |
Funds report holdings monthly or quarterly; dates differ by fund.
OSBC insider transactions
latest 6| Date | Name | Transaction | Price | Shares | Value |
|---|---|---|---|---|---|
| 2026-02-18 | Darin Patrick Campbell | Sell | $20.94 | 35,000 | $732,900 |
| 2026-02-13 | Darin Patrick Campbell | Sell | $20.70 | 91 | $1,884 |
| 2026-02-05 | Richard A Gartelmann Jr | Sell | $20.98 | 2,000 | $41,960 |
| 2025-10-31 | Darin Patrick Campbell | Sell | $17.89 | 31,159 | $557,435 |
| 2025-10-30 | Darin Patrick Campbell | Sell | $18.27 | 26,406 | $482,438 |
| 2025-08-04 | Billy J Jr. Lyons | Buy | $16.61 | 25 | $415 |
Reported trades by company officers, directors and other filers (including disclosures by members of Congress where EODHD lists them). "—" where the filing gives no share count.
OSBC shares outstanding
Year-end shares outstanding, adjusted for splits.
Who owns OSBC
Institutional investors own 79.1% of Old Second Bancorp's shares and insiders 4.33%. The largest holder is BlackRock Inc with 8.45% of the shares (4.3M), as of June 30, 2026. Among the top 20 institutions, 9 added shares and 10 reduced their stake in the latest filings. Short interest is 5.60% of the float, or 5.73 days of average trading volume. The share count rose 67.8% since 2014.
Related: OSBC analyst forecast, OSBC key metrics, OSBC dividend history. See the OSBC stock overview for the latest quote and news.
OSBC ownership FAQ
Who owns the most Old Second Bancorp stock?
The largest shareholders of Old Second Bancorp are BlackRock Inc (8.45%), Dimensional Fund Advisors, Inc. (4.91%), Vanguard Capital Management, LLC (4.28%), State Street Corp (3.62%), Davis Asset Management, L.P. (3.54%).
What percentage of Old Second Bancorp is owned by institutions?
Institutions hold 79.1% of Old Second Bancorp's shares outstanding; insiders hold 4.33%.
Which funds own Old Second Bancorp?
The largest fund holders of Old Second Bancorp are Avantis US Small Cap Value ETF (3.19%), Vanguard MStar Total Stk Mkt Idx Invest (3.05%), iShares Russell 2000 ETF (2.67%), Fidelity Small Cap Index (1.08%), State Street® SPDR® S&PRgnllBkgETF (1.00%).
What is Old Second Bancorp's short interest?
2.7M shares of Old Second Bancorp were sold short, 5.60% of the float; at the average daily volume it would take 5.73 days to cover.
Are insiders buying or selling Old Second Bancorp?
Of the latest 6 reported insider transactions in Old Second Bancorp (since August 4, 2025), 1 were purchases and 5 were sales.
How many shares of Old Second Bancorp are outstanding?
Old Second Bancorp has 50.9M shares outstanding, of which 49.2M are in the public float.