OSBC Institutional Ownership & Shareholders
OLD SECOND BANCORP INC (OSBC) is currently held by 183 institutional investors tracked by InsiderSet, with a combined reported market value of approximately $883.39M based on the latest available SEC Form 13F filings for the quarter ended June 30, 2026.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of OSBC tracked by InsiderSet, reporting ownership valued at approximately $100.25M in its June 30, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $104.46M, representing an estimated gain of +4.20% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 53% of the total disclosed OSBC value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Dimensional Fund Advisors Lp, Vanguard Capital Management Llc, and several other long-term asset managers with concentrated positions in OLD SECOND BANCORP INC (OSBC).
This page ranks the largest institutional OSBC shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
183
Total Reported Value
$883.39M
Largest Holder
Blackrock, Inc.
Largest Position
$100.25M
Insider Transactions (90d)
15
Latest Filing Quarter
Q2 2026
New Institutional Positions
45
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.00% | 4,298,683 | $100,245,292 | $104,457,997 | +$4,212,705 | +4.20% | |
| Dimensional Fund Advisors Lp | 0.01% | 2,498,671 | $58,268,836 | $60,717,705 | +$2,448,869 | +4.20% | |
| Vanguard Capital Management Llc | 0.00% | 2,179,877 | $50,834,732 | $52,971,011 | +$2,136,279 | +4.20% | |
| State Street Corp | 0.00% | 1,839,202 | $42,887,045 | $44,692,609 | +$1,805,564 | +4.21% | |
| Davis Asset Management, L.P. | 1.06% | 1,800,000 | $41,976,000 | $43,740,000 | +$1,764,000 | +4.20% | |
| American Century Companies Inc | 0.02% | 1,783,820 | $41,598,684 | $43,346,826 | +$1,748,142 | +4.20% | |
| Goldman Sachs Group Inc | 0.00% | 1,624,852 | $37,891,548 | $39,483,904 | +$1,592,356 | +4.20% | |
| Fj Capital Management Llc | 4.42% | 1,460,413 | $34,056,831 | $35,488,036 | +$1,431,205 | +4.20% | |
| Boston Partners | 0.03% | 1,415,165 | $32,924,716 | $34,388,510 | +$1,463,794 | +4.45% | |
| Geode Capital Management, Llc | 0.00% | 1,349,432 | $31,474,650 | $32,791,198 | +$1,316,548 | +4.18% | |
| Kennedy Capital Management Llc | 0.51% | 1,236,983 | $28,846,444 | $30,058,687 | +$1,212,243 | +4.20% | |
| Banc Funds Co Llc | 3.98% | 1,034,143 | $24,116,215 | $25,129,675 | +$1,013,460 | +4.20% | |
| Manufacturers Life Insurance Company, The | 0.02% | 872,651 | $20,350,221 | $21,205,419 | +$855,198 | +4.20% | |
| Vanguard Portfolio Management Llc | 0.00% | 819,368 | $19,107,662 | $19,910,642 | +$802,980 | +4.20% | |
| Stieven Capital Advisors, L.P. | 3.63% | 815,328 | $19,013,449 | $19,812,470 | +$799,021 | +4.20% | |
| Northern Trust Corp | 0.00% | 555,408 | $12,952,115 | $13,496,414 | +$544,299 | +4.20% | |
| Alliancebernstein L.P. | 0.00% | 641,845 | $12,939,595 | $15,596,834 | +$2,657,239 | +20.54% | |
| Jpmorgan Chase & Co | 0.00% | 555,602 | $12,895,522 | $13,501,129 | +$605,607 | +4.70% | |
| Wellington Management Group Llp | 0.00% | 544,345 | $12,694,125 | $13,227,584 | +$533,459 | +4.20% | |
| Nuveen, Llc | 0.00% | 492,162 | $11,477,218 | $11,959,537 | +$482,319 | +4.20% | |
| Bridgeway Capital Management, Llc | 0.19% | 453,323 | $10,571,492 | $11,015,749 | +$444,257 | +4.20% | |
| Congress Asset Management Co | 0.07% | 411,201 | $10,070,312 | $9,992,184 | -$78,128 | -0.78% | |
| Charles Schwab Investment Management Inc | 0.00% | 431,304 | $10,058,009 | $10,480,687 | +$422,678 | +4.20% | |
| Aqr Capital Management Llc | 0.00% | 386,234 | $9,006,974 | $9,385,486 | +$378,512 | +4.20% | |
| Bank Of America Corp | 0.00% | 372,648 | $8,690,151 | $9,055,346 | +$365,195 | +4.20% | |
| Gator Capital Management, Llc | 1.81% | 359,730 | $8,388,904 | $8,741,439 | +$352,535 | +4.20% | |
| Bank Of New York Mellon Corp | 0.00% | 342,013 | $7,975,752 | $8,310,916 | +$335,164 | +4.20% | |
| Vanguard Fiduciary Trust Co | 0.00% | 341,200 | $7,956,784 | $8,291,160 | +$334,376 | +4.20% | |
| Morgan Stanley | 0.00% | 318,318 | $7,423,207 | $7,735,127 | +$311,920 | +4.20% | |
| Citadel Advisors Llc | 0.00% | 304,021 | $7,089,770 | $7,387,710 | +$297,940 | +4.20% | |
| Forum Financial Management, Lp | 0.08% | 237,367 | $5,813,124 | $5,768,018 | -$45,106 | -0.78% | |
| Empowered Funds, Llc | 0.03% | 248,627 | $5,797,982 | $6,041,636 | +$243,654 | +4.20% | |
| Thrivent Financial For Lutherans | 0.01% | 242,278 | $5,650,000 | $5,887,355 | +$237,355 | +4.20% | |
| Mariner, Llc | 0.01% | 225,303 | $5,254,044 | $5,474,863 | +$220,819 | +4.20% | |
| Arrowstreet Capital, Limited Partnership | 0.00% | 210,745 | $4,914,573 | $5,121,104 | +$206,531 | +4.20% | |
| Great Lakes Advisors, Llc | 0.04% | 203,909 | $4,755,158 | $4,954,989 | +$199,831 | +4.20% | |
| Two Sigma Investments, Lp | 0.00% | 200,819 | $4,683,099 | $4,879,902 | +$196,803 | +4.20% | |
| Squarepoint Ops Llc | 0.01% | 167,884 | $3,915,055 | $4,079,581 | +$164,526 | +4.20% | |
| Blair William & Co/Il | 0.01% | 163,228 | $3,806,470 | $3,966,440 | +$159,970 | +4.20% | |
| Siena Capital Partners Gp, Llc | 0.92% | 163,038 | $3,805,307 | $3,961,823 | +$156,516 | +4.11% | |
| Ejf Capital Lp | 2.36% | 151,358 | $3,529,669 | $3,677,999 | +$148,330 | +4.20% | |
| Ubs Group Ag | 0.00% | 147,223 | $3,433,240 | $3,577,519 | +$144,279 | +4.20% | |
| Victory Capital Management Inc | 0.00% | 141,914 | $3,309,434 | $3,448,510 | +$139,076 | +4.20% | |
| Principal Financial Group Inc | 0.00% | 134,253 | $3,287,856 | $3,262,348 | -$25,508 | -0.78% | |
| Russell Investments Group, Ltd. | 0.00% | 135,010 | $3,148,432 | $3,280,743 | +$132,311 | +4.20% | |
| Elizabeth Park Capital Advisors, Ltd. | 2.09% | 129,457 | $3,018,937 | $3,145,805 | +$126,868 | +4.20% | |
| Sei Investments Co | 0.00% | 117,666 | $2,743,974 | $2,859,284 | +$115,310 | +4.20% | |
| D. E. Shaw & Co., Inc. | 0.00% | 114,326 | $2,666,082 | $2,778,122 | +$112,040 | +4.20% | |
| Curi Capital, Llc | 0.04% | 100,505 | $2,343,777 | $2,442,272 | +$98,495 | +4.20% | |
| Swiss National Bank | 0.00% | 100,400 | $2,341,328 | $2,439,720 | +$98,392 | +4.20% |
Frequently asked questions about OSBC
Who are the largest institutional holders of OSBC?
The largest institutional holders of OSBC reported in the latest SEC Form 13F filings include Blackrock, Inc., Dimensional Fund Advisors Lp, Vanguard Capital Management Llc, State Street Corp, and Davis Asset Management, L.P.. InsiderSet ranks institutional holders by their latest reported OSBC position.
What is OSBC institutional ownership?
This page tracks OSBC positions reported by institutional investment managers through SEC Form 13F. OLD SECOND BANCORP INC (OSBC) institutional ownership on InsiderSet reflects disclosed 13F holdings among the managers we analyze, not every shareholder of the stock.
How many institutions own OSBC?
InsiderSet currently tracks 183 institutional managers reporting OSBC holdings in the latest available 13F data. This count reflects institutions included in the SEC Form 13F filings analyzed by InsiderSet and should not be interpreted as the total number of OSBC shareholders.
How much OSBC stock do institutions own?
Institutional investment managers disclosed approximately $883.39M in OSBC holdings for Q2 2026. This figure is reported 13F value as of the filing period, not necessarily today's market value.
When was OSBC institutional ownership last updated?
The latest OSBC institutional ownership data on InsiderSet is based on SEC Form 13F filings for the quarter ended June 30, 2026. Form 13F filings are generally reported after the quarter ends, so the holdings shown represent the latest publicly disclosed positions rather than real-time institutional holdings.
Are institutional OSBC holdings real-time?
No. Form 13F data is not real-time. It represents positions reported by institutional investment managers as of the end of the reporting quarter. An institution may have changed its OSBC position after the reporting date.
Are institutions buying or selling OSBC?
Institutional buying and selling can be analyzed by comparing OSBC positions across consecutive 13F reporting periods. InsiderSet's OSBC Ownership Changes page shows institutions that increased, reduced, initiated, or exited positions based on reported 13F holdings. View OSBC ownership changes.
How has OSBC institutional ownership changed over time?
InsiderSet tracks OSBC institutional holdings across multiple 13F reporting periods, allowing investors to compare institutional holder counts, reported value, and reported shares over time.