Institutional ownership · Form 13F

OSBC institutional ownership

Old Second Bancorp, Inc. - Common Stock: reported institutional holdings as of 2026-06-30 (filed through 2026-08-31), aggregated by StockEyes from SEC Form 13F information tables. OSBC is one of 2732 tickers in the validated publication set. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.

Quarter ended2026-06-30 Filed through2026-08-31 Reporting managers184 Reported shares38,827,074 Value as filed$893,256,777
What changed this quarter

OSBC: change since the prior quarter's filings

Fewer managers reported a position, with the count falling from 188 in the quarter ended 2026-03-31 to 184 in the quarter ended 2026-06-30 (-4, 2.1%). Total reported shares rose to 38,827,074 (+1,044,490, 2.8%), against the direction of the manager count. Among the 29 managers listed as top holders in both quarters, the largest increases were STATE STREET CORP (+239,900 shares) and AMERICAN CENTURY COMPANIES INC (+192,877 shares), among 17 managers who added shares, and the largest decreases were WELLINGTON MANAGEMENT GROUP LLP (-313,440 shares) and NORTHERN TRUST CORP (-208,933 shares), among 11 managers who reduced shares. CONGRESS ASSET MANAGEMENT CO (338,650 shares) entered the listed top holders; UBS Group AG (259,274 shares in the prior quarter) dropped out of the listed top holders.

New to 13F data? Read how to read a 13F filing, or see where institutions moved overall in the Smart Money Report.

As filed

Reported totals, quarter ended 2026-06-30

184 reporting managers held 38,827,074 shares, reported value $893,256,777 exactly as filed. Values are position values transcribed from the filings, not current market prices.

Reported quarter-over-quarter change (quarter ended 2026-03-31 to quarter ended 2026-06-30): reporting managers -4, reported shares +1,044,490 (+2.76%), reported value +18.25%. These changes compare two filing snapshots.

Shares outstanding check: 51,846,961 shares reported by the issuer (SEC XBRL, period ended 2026-06-30). Reported 13F shares equal 74.9% of that figure. This page passed the publication sanity gate before listing.

What the data shows

OSBC in this quarter's filings

Concentration check: the largest reported position, BlackRock, Inc. with 4,298,683 shares, is 11.1% of all shares reported for OSBC this quarter. The five largest reporting managers together account for 32.5% of the reported total, so the headline total is spread across a broad manager base rather than a few holders.

Reported quarter-over-quarter change: the reporting-manager count fell by 4 versus the quarter ended 2026-03-31, and reported shares moved +2.76% (+1,044,490 shares). That is a comparison of two filing snapshots, not a record of trades on any single day.

Shares-outstanding cross-check: reported 13F shares equal 74.9% of the issuer share count used at the publication gate (51,846,961 shares, issuer period ended 2026-06-30). The gate publishes a ticker only when that relationship is plausible; lending chains can push reported totals above a simple ownership share, which is why the figure is a sanity check and not an ownership percentage.

Top holders as filed

Largest reporting managers, OSBC

OSBC largest 13F reporting managers, quarter ended 2026-06-30
#ManagerSharesValue as filedShare of reported total
1BlackRock, Inc.4,298,683$100,245,29211.1%
2DIMENSIONAL FUND ADVISORS LP2,498,671$58,268,8366.4%
3VANGUARD CAPITAL MANAGEMENT LLC2,179,877$50,834,7325.6%
4STATE STREET CORP1,839,202$42,887,0454.7%
5Davis Asset Management, L.P.1,800,000$41,976,0004.6%
6AMERICAN CENTURY COMPANIES INC1,783,820$41,598,6844.6%
7GOLDMAN SACHS GROUP INC1,624,852$37,891,5484.2%
8FJ Capital Management LLC1,460,413$34,056,8313.8%
9Boston Partners1,415,165$32,924,7163.6%
10GEODE CAPITAL MANAGEMENT, LLC1,349,432$31,474,6503.5%
11KENNEDY CAPITAL MANAGEMENT LLC1,236,983$28,846,4443.2%
12BANC FUNDS CO LLC1,034,143$24,116,2152.7%
13MANUFACTURERS LIFE INSURANCE COMPANY, THE872,651$20,350,2212.2%
14VANGUARD PORTFOLIO MANAGEMENT LLC819,368$19,107,6622.1%
15Stieven Capital Advisors, L.P.815,328$19,013,4492.1%

Manager names and figures are transcribed from each manager's own Form 13F information table. A manager listing shares in this snapshot does not mean it holds them today.

Quarter comparison

Reported change, 2026-03-31 to 2026-06-30

OSBC reported 13F totals by quarter
Quarter endedFiled throughReporting managersReported sharesValue as filed
2026-03-312026-05-2918837,782,584$755,413,199
2026-06-302026-08-3118438,827,074$893,256,777

Every change figure on this page is a reported quarter-over-quarter change between filing snapshots. It is not real-time trading activity.

Reported history

OSBC reported totals over time

Quarter ended 2026-06-30: 184 reporting managers · 38,827,074 reported shares · $893,256,777 value as filed.

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Quarter-end 13F filed data, long positions only; filings arrive up to 45 days after quarter end.

Coverage for this ticker

CUSIPs behind the OSBC total

The validated bridge mapped 1 current CUSIP(s) to OSBC for this quarter: 680277100. Option pseudo-CUSIPs, units, warrants, and preferred classes are excluded from these common-share totals. Mapping coverage in this publication set: 4562 of 6046 universe tickers have at least one validated CUSIP mapping (75.5%). Latest-quarter filed value resolved to any listed ticker: 77.3%; resolved to this universe: 77.2%.

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What this page is and is not

Form 13F reports are quarterly holdings snapshots. Managers file up to about 45 days after quarter-end, so these figures describe reported positions as of the quarter-end date, not holdings today. 13F lists reportable long positions from managers above the SEC reporting threshold and omits short positions entirely.

This page is informational only. It is not investment advice, a recommendation, or a signal to buy or sell. Source: SEC Form 13F bulk data set for filings through 2026-08-31 (period ended 2026-06-30), joined to tickers through StockEyes' validated CUSIP bridge. Methodology and coverage are documented on the institutional ownership hub.

Insider transactions for OSBC (officer and director buys and sells) are covered by InsiderTrace: insidertrace.com/stock/osbc. StockEyes does not duplicate insider transaction tables.

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Related StockEyes pages

Latest headlines tagged OSBC are on the market news wire. Upcoming earnings and market dates are on the events calendar. The term itself is defined in the institutional investor glossary entry, and the research workflow behind pages like this one is walked through in how to research a stock and how to compare SEC filings.

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