$OSBC

$24.60 -$0.17 (0.69%) Close

$OSBC Overview Financial Statements SEC Filings Executives News Red Flags Capital Raising Ownership Insider Transactions Congressional Trades

Ownership

13F as of Q2 2026 · 50.9M shares outstanding

Who owns OSBC?

By type of holder

Institutions 76.2% Insiders 1.1% Everyone else 22.6%

Concentration Top 10 holders own 39.8%

BlackRock, Inc. 8.5% · Dimensional Fund Advisors LP 4.9%

Institutional ownership

76.2%

+2.0 pts vs last qtr

Institutional holders

183

-5 vs last qtr

Net shares bought

+996.4K

by institutions in Q2 2026

New / sold out

19 / 24

positions opened vs closed

How is ownership changing?

Institutions, last 8 quarters

Biggest buyers in Q2 2026

Congress Asset Management Co NEW +338.7K
Citadel Advisors LLC +244.0K

Biggest sellers in Q2 2026

Wellington Management Group LLP −313.4K
Northern Trust Corp −208.9K

Who is planning to sell?

Notices of proposed sale, last 12 months

$3.65M

4 notices from 4 people

Shares covered

144.0K

0.28% of the company

Arranged in advance

52%

of the value is under a 10b5-1 plan

Under a 10b5-1 plan No plan

Largest proposed sellers

Eccher James Officer 10b5-1 $1.9M
Hugh H. Mclean Director $642K

Every notice on Red Flags →

A Form 144 is notice of a planned sale, not the sale itself. What insiders actually sold is on Insider Transactions.

Is your stake being diluted?

Diluted share count, FY2016–FY2025

+66.5%

+5.83% a year

Each share's claim on the business

−39.9%

shrank without buying or selling a share

Spent on buybacks vs paid in stock

$27.5M vs $26.2M

over 10 fiscal years

Diluted shares, split-adjusted

Buybacks Stock-based comp

How patient are the owners?

Institutional shares by how long they've been held

5+ years71% 3–5 years7% 1–3 years12% Under 1 year10%

Quarterly turnover

7.1%

of institutional shares changed hands

Top 10 managers, median time held

5 years

Super Investors

Investment managers reporting OSBC on Form 13F

Holder	Shares	% of company	Change vs last qtr	Held since	% of their book
B BlackRock, Inc.	4.3M	8.45%	+172.4K (+4.2%)	≤2021	0.0%
Shares held by quarter Peak holding4.3M (Q2'26) Change over 8 quarters+618.6K Share of the company8.450% BlackRock, Inc.'s full portfolio →
DF Dimensional Fund Advisors LP	2.5M	4.91%	+109.8K (+4.6%)	≤2021	0.0%
Shares held by quarter Peak holding2.5M (Q2'26) Change over 8 quarters+613.7K Share of the company4.910% Dimensional Fund Advisors LP's full portfolio →

BlackRock, Inc.

4.3M

% of company

8.45%

Change vs last qtr

+172.4K (+4.2%)

Held since

≤2021

Dimensional Fund Advisors LP

2.5M

% of company

4.91%

Change vs last qtr

+109.8K (+4.6%)

Held since

≤2021

28 more super investors behind a free account

See every manager holding Old Second Bancorp, Inc, how their position has changed, and how long they've held it.

Institutional Funds

Mutual funds and ETFs reporting OSBC on Form N-PORT; together they hold 32.4% of the company

Fund	Position value	Shares	% of company	% of the fund	As of
VT Vanguard Total Stock Market Index Fund Vanguard Index Funds	$35.8M	1.5M	3.02%	0.00%	June 30, 2026
IR iShares Russell 2000 ETF iShares Trust	$30.9M	1.3M	2.60%	0.04%	June 30, 2026

Vanguard Total Stock Market Index Fund

Vanguard Index Funds

Position value

$35.8M

% of company

3.02%

% of the fund

0.00%

As of

June 30, 2026

iShares Russell 2000 ETF

iShares Trust

Position value

$30.9M

% of company

2.60%

% of the fund

0.04%

As of

June 30, 2026

23 more funds behind a free account

See every fund holding Old Second Bancorp, Inc and how much of the fund the position is.

Insiders and 5%+ holders

From Forms 3/4/5 and Schedules 13D/G

Holder	Shares	% of company	Change vs last qtr	8 quarters	Held since	% of their book
LJ Ladowicz John Insider	579.8K	1.14%	—	—	—	—
Insider holdings come from Form 3/4/5 filings, which are not quarterly. Share of the company1.140% Ladowicz John's insider activity →

Ladowicz John

Insider

579.8K

% of company

1.14%

Change vs last qtr

—

Held since

—

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