Comparable stake leader
FJ Capital Management LLC
SEC ownership of OLD SECOND BANCORP INC
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0000357173.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
31 Mar 2026
- Public ticker
- OSBC on Nasdaq
- Parsed ownership sources
- 13F, 13D/G, and 3/4/5
- Largest SEC-reported holder
- FJ Capital Management LLC
- Latest 13D/G holder
- FJ Capital Management LLC
- Latest parsed ownership date
- 31 Mar 2026
- Issuer CIK
- 0000357173
- Issuer location
- Aurora, IL
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
2 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of OLD SECOND BANCORP INC (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
FJ Capital Management LLC
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
31 Mar 2026
13F
13D/G
3/4/5
Lead comparable stake: 4.2%
13D/G row: FJ Capital Management LLC
Showing 1-8 of 50 holder rows.
Quick read
FJ Capital Management LLC leads the comparable SEC ownership view at 4.2%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens FJ Capital Management LLC's linked filing trail.
Comparable ownership
Top 5
FJ Capital Management LLC
4.2%
John Ladowicz
0.4%
BlackRock, Inc.
9.2%
DIMENSIONAL FUND ADVISORS LP
5.3%
VANGUARD CAPITAL MANAGEMENT LLC
5%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| FJ Capital Management LLC |
13F
13D/G
Company
|
4.2%
from 13D/G
|
$30,342,856
1,505,102 shares
|
— | 31 Mar 2026 |
| John Ladowicz |
3/4/5
Director
|
0.4%
|
$3,741,295
181,013 shares
|
-$599,747 | 15 Jan 2026 |
| BlackRock, Inc. |
13F
Company
|
9.2%
|
$83,185,084
4,126,244 shares
|
— | 31 Mar 2026 |
| DIMENSIONAL FUND ADVISORS LP |
13F
Company
|
5.3%
|
$48,158,712
2,388,862 shares
|
— | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13F
Company
|
5%
|
$45,397,276
2,251,849 shares
|
— | 31 Mar 2026 |
| Davis Asset Management, L.P. |
13F
Company
|
4%
|
$36,288,000
1,800,000 shares
|
— | 31 Mar 2026 |
| GOLDMAN SACHS GROUP INC |
13F
Company
|
3.8%
|
$34,101,103
1,691,523 shares
|
— | 31 Mar 2026 |
| STATE STREET CORP |
13F
Company
|
3.6%
|
$32,241,928
1,599,302 shares
|
— | 31 Mar 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to selling over the last 12 months. Net value: -$4,001,296.
Buys
$917
Insiders: 1
Sells
$4,002,213
Insiders: 5
Net
-$4,001,296
Shares: -202,293
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 49
Shares: 202,342
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 24 | 77,274 | $502 | $1,586,090 | -$1,585,588 |
| 3-6 | 0 | 54,353 | $0 | $1,126,490 | -$1,126,490 |
| 6-9 | 0 | 70,715 | $0 | $1,289,633 | -$1,289,633 |
| 9-12 | 25 | 0 | $415 | $0 | +$415 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 21 reporting-owner rows connected to OLD SECOND BANCORP INC. Open a relationship link for the CIK-to-CIK filing trail.
Rows
21
Largest Forms 3/4/5 holder
James Eccher
Net 12M change
-$4,001,296
Latest report
22 May 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| James Eccher | CHAIRMAN AND CEO, Director | $12,541,162 | Mixed | 31 Mar 2026 | ||
| Keith Acker | Director | $11,440,102 | Mixed | 01 Dec 2021 | ||
| Darin Patrick Campbell | President, Powersports Lending, Director | $5,486,288 | -$1,774,426 | -24% | Mixed | 18 Feb 2026 |
| Bradley S. Adams | Cfo & Coo | $5,257,976 | Mixed | 31 Mar 2026 | ||
| Keith Kotche | Director | $3,901,931 | Mixed | 17 Feb 2026 | ||
| John Ladowicz | Director | $3,741,295 | -$599,747 | -14% | Mixed | 15 Jan 2026 |
| Edward Bonifas | Director | $3,659,573 | Mixed | 21 Feb 2026 | ||
| Hugh H. Mclean | Director | $3,360,273 | Mixed | 17 Feb 2026 | ||
| Gary S. Collins | VICE CHAIRMAN, Director | $2,914,792 | -$1,067,295 | -27% | Mixed | 22 May 2026 |
| Donald Pilmer | Evp | $2,031,819 | -$518,795 | -20% | Mixed | 11 May 2026 |
| Barry Finn | Director | $1,929,425 | Mixed | 17 Feb 2026 | ||
| Richard A. Gartelmann Jr. | Evp | $1,313,252 | -$41,950 | -3.1% | Mixed | 31 Mar 2026 |
| Dennis L. Klaeser | Director | $1,210,085 | Mixed | 17 Feb 2026 | ||
| Rocks Patti Temple | Director | $997,754 | Mixed | 17 Feb 2026 | ||
| John Williams Jr. | Director | $953,802 | Mixed | 17 Feb 2026 | ||
| William Kane | Director | $863,478 | Mixed | 21 Feb 2023 | ||
| William B. Skoglund | Director | $718,566 | Mixed | 25 Jul 2023 | ||
| Jill E. York | Director | $711,504 | Mixed | 17 Feb 2026 | ||
| Duane Suits | Director | $647,615 | Mixed | 15 Feb 2022 | ||
| Billy J. Lyons Jr. | Director | $637,966 | +$917 | +0.14% | Mixed | 11 May 2026 |
Recent insider transactions for OLD SECOND BANCORP INC
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -8.09% | $108,134 | $21.12 | -5,120 | 58,136 | 22 May 2026 | IRA |
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -13.6% | $211,200 | $21.12 | -10,000 | 63,256 | 21 May 2026 | IRA |
| Billy J. Lyons Jr. | OSBC | Old Second Bancorp, Inc. Common Stock | Purchase | 0.12% | $502 | $20.90 | 24 | 20,097 | 11 May 2026 | Direct |
| Donald Pilmer | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -34.2% | $518,795 | $20.75 | -25,000 | 48,054 | 11 May 2026 | Direct |
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -6.39% | $106,125 | $21.22 | -5,000 | 73,256 | 08 May 2026 | IRA |
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -24.9% | $212,400 | $21.24 | -10,000 | 30,136 | 08 May 2026 | Direct |
| Bradley S. Adams | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 0.35% | 35 | 10,159 | 31 Mar 2026 | By 401-k Plan | ||
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 3.72% | 253 | 7,058 | 31 Mar 2026 | By 401-K | ||
| Donald Pilmer | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 0.55% | 1 | 183 | 31 Mar 2026 | By Profit Sharing Plan | ||
| Donald Pilmer | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 0.32% | 13 | 4,023 | 31 Mar 2026 | By 401-K Plan | ||
| James Eccher | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 0.35% | 22 | 6,357 | 31 Mar 2026 | By Profit Sharing | ||
| James Eccher | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 1.12% | 369 | 33,387 | 31 Mar 2026 | By 401-K | ||
| Richard A. Gartelmann Jr. | OSBC | Old Second Bancorp, Inc. Common Stock | Other | 0.34% | 43 | 12,606 | 31 Mar 2026 | By 401-K | ||
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -35.6% | $429,435 | $19.38 | -22,154 | 40,136 | 20 Mar 2026 | Direct |
| Bradley S. Adams | OSBC | Old Second Bancorp, Inc. Common Stock | Tax liability | -2.78% | -4,587 | 160,401 | 02 Mar 2026 | Direct | ||
| Bradley S. Adams | OSBC | Old Second Bancorp, Inc. Common Stock | Award | 10.5% | 15,657 | 164,988 | 02 Mar 2026 | Direct | ||
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Tax liability | -21.2% | -4,228 | 15,666 | 02 Mar 2026 | Direct | ||
| Gary S. Collins | OSBC | Old Second Bancorp, Inc. Common Stock | Award | 14,432 | 5,462 | 02 Mar 2026 | Direct | |||
| Donald Pilmer | OSBC | Old Second Bancorp, Inc. Common Stock | Tax liability | -3.59% | -2,720 | 73,054 | 02 Mar 2026 | Direct | ||
| Donald Pilmer | OSBC | Old Second Bancorp, Inc. Common Stock | Award | 16% | 9,201 | 66,573 | 02 Mar 2026 | Direct | ||
| Richard A. Gartelmann Jr. | OSBC | Old Second Bancorp, Inc. Common Stock | Tax liability | -4.94% | -1,537 | 29,551 | 02 Mar 2026 | Direct | ||
| Richard A. Gartelmann Jr. | OSBC | Old Second Bancorp, Inc. Common Stock | Award | 20.5% | 4,523 | 26,565 | 02 Mar 2026 | Direct | ||
| James Eccher | OSBC | Old Second Bancorp, Inc. Common Stock | Tax liability | -3.28% | -12,838 | 378,399 | 02 Mar 2026 | Direct | ||
| James Eccher | OSBC | Old Second Bancorp, Inc. Common Stock | Award | 12.6% | 43,818 | 391,237 | 02 Mar 2026 | Direct | ||
| Jill E. York | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| John Williams Jr. | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Rocks Patti Temple | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Hugh H. Mclean | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Billy J. Lyons Jr. | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Keith Kotche | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Dennis L. Klaeser | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Barry Finn | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Edward Bonifas | OSBC | Restricted Stock Units | Tax liability | -22.5% | -3,077 | 10,595 | 21 Feb 2026 | Direct | ||
| Gary S. Collins | OSBC | Restricted Stock Units | Tax liability | -5.76% | -2,784 | 45,558 | 21 Feb 2026 | Direct | ||
| James Eccher | OSBC | Restricted Stock Units | Tax liability | -3.4% | -7,515 | 213,290 | 21 Feb 2026 | Direct | ||
| Donald Pilmer | OSBC | Restricted Stock Units | Tax liability | -3.9% | -1,818 | 44,754 | 21 Feb 2026 | Direct | ||
| Richard A. Gartelmann Jr. | OSBC | Restricted Stock Units | Tax liability | -3.61% | -894 | 23,879 | 21 Feb 2026 | Direct | ||
| Bradley S. Adams | OSBC | Restricted Stock Units | Tax liability | -3.02% | -2,923 | 93,926 | 21 Feb 2026 | Direct | ||
| Darin Patrick Campbell | OSBC | Old Second Bancorp, Inc. Common Stock | Sale | -11.3% | $732,900 | $20.94 | -35,000 | 274,589 | 18 Feb 2026 | Direct |
| Jill E. York | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| John Williams Jr. | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Rocks Patti Temple | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Hugh H. Mclean | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Billy J. Lyons Jr. | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Keith Kotche | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Dennis L. Klaeser | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Barry Finn | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Edward Bonifas | OSBC | Restricted Stock Units | Award | 29.6% | 3,121 | 13,672 | 17 Feb 2026 | Direct | ||
| Gary S. Collins | OSBC | Restricted Stock Units | Award | 19.7% | 8,858 | 53,804 | 17 Feb 2026 | Direct | ||
| James Eccher | OSBC | Restricted Stock Units | Award | 29.3% | 54,010 | 238,328 | 17 Feb 2026 | Direct |
* marks a reported price that did not pass the local price check.