OLD SECOND BANCORP INC (OSBC) Top Institutional Shareholders
OLD SECOND BANCORP INC (OSBC) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended March 31, 2026. The institutional investors covered on this page collectively reported approximately $741.47M in OSBC holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of OSBC tracked by InsiderSet, reporting ownership valued at approximately $83.19M in its March 31, 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 $89.37M, representing an estimated gain of +7.44% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 54% 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
186
Total Reported Value
$741.47M
Largest Holder
Blackrock, Inc.
Largest Position
$83.19M
Insider Transactions (90d)
0
Latest Filing Quarter
Q1 2026
New Institutional Positions
171
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% | 4,126,244 | $83,185,084 | $89,374,445 | +$6,189,361 | +7.44% | |
| Dimensional Fund Advisors Lp | 0.01% | 2,388,862 | $48,158,712 | $51,742,751 | +$3,584,039 | +7.44% | |
| Vanguard Capital Management Llc | 0.00% | 2,251,849 | $45,397,276 | $48,775,049 | +$3,377,773 | +7.44% | |
| Davis Asset Management, L.P. | 1.05% | 1,800,000 | $36,288,000 | $38,988,000 | +$2,700,000 | +7.44% | |
| Goldman Sachs Group Inc | 0.00% | 1,691,523 | $34,101,103 | $36,638,388 | +$2,537,285 | +7.44% | |
| State Street Corp | 0.00% | 1,599,302 | $32,241,928 | $34,640,881 | +$2,398,953 | +7.44% | |
| American Century Companies Inc | 0.02% | 1,590,943 | $32,073,412 | $34,459,825 | +$2,386,413 | +7.44% | |
| Fj Capital Management Llc | 3.42% | 1,505,102 | $30,342,856 | $32,600,509 | +$2,257,653 | +7.44% | |
| Boston Partners | 0.03% | 1,443,889 | $29,278,530 | $31,274,636 | +$1,996,106 | +6.82% | |
| Geode Capital Management, Llc | 0.00% | 1,282,011 | $25,852,061 | $27,768,358 | +$1,916,297 | +7.41% | |
| Kennedy Capital Management Llc | 0.54% | 1,268,490 | $25,572,758 | $27,475,493 | +$1,902,735 | +7.44% | |
| Banc Funds Co Llc | 3.86% | 1,029,143 | $20,747,523 | $22,291,237 | +$1,543,714 | +7.44% | |
| Manufacturers Life Insurance Company, The | 0.02% | 878,670 | $17,713,987 | $19,031,992 | +$1,318,005 | +7.44% | |
| Wellington Management Group Llp | 0.00% | 857,785 | $17,292,946 | $18,579,623 | +$1,286,677 | +7.44% | |
| Stieven Capital Advisors, L.P. | 3.33% | 773,528 | $15,594,324 | $16,754,616 | +$1,160,292 | +7.44% | |
| Northern Trust Corp | 0.00% | 764,341 | $15,409,115 | $16,555,626 | +$1,146,511 | +7.44% | |
| River Street Advisors Llc | 5.09% | 746,660 | $15,052,662 | $16,172,656 | +$1,119,994 | +7.44% | |
| Vanguard Portfolio Management Llc | 0.00% | 712,433 | $14,362,649 | $15,431,299 | +$1,068,650 | +7.44% | |
| Alliancebernstein L.P. | 0.00% | 690,845 | $13,471,478 | $14,963,703 | +$1,492,225 | +11.08% | |
| Bridgeway Capital Management, Llc | 0.18% | 438,255 | $8,835,221 | $9,492,603 | +$657,382 | +7.44% | |
| Charles Schwab Investment Management Inc | 0.00% | 430,910 | $8,687,146 | $9,333,511 | +$646,365 | +7.44% | |
| Nuveen, Llc | 0.00% | 419,642 | $8,459,982 | $9,089,446 | +$629,464 | +7.44% | |
| Aqr Capital Management Llc | 0.00% | 391,960 | $7,901,908 | $8,489,854 | +$587,946 | +7.44% | |
| Gator Capital Management, Llc | 1.51% | 351,480 | $7,085,837 | $7,613,057 | +$527,220 | +7.44% | |
| Bank Of New York Mellon Corp | 0.00% | 337,264 | $6,799,251 | $7,305,138 | +$505,887 | +7.44% | |
| Vanguard Fiduciary Trust Co | 0.00% | 335,483 | $6,763,337 | $7,266,562 | +$503,225 | +7.44% | |
| Bank Of America Corp | 0.00% | 331,330 | $6,679,612 | $7,176,608 | +$496,996 | +7.44% | |
| Morgan Stanley | 0.00% | 278,387 | $5,612,306 | $6,029,862 | +$417,556 | +7.44% | |
| Ubs Group Ag | 0.00% | 259,274 | $5,226,964 | $5,615,875 | +$388,911 | +7.44% | |
| Empowered Funds, Llc | 0.03% | 233,559 | $4,708,549 | $5,058,888 | +$350,339 | +7.44% | |
| Forum Financial Management, Lp | 0.06% | 205,661 | $4,146,131 | $4,454,617 | +$308,486 | +7.44% | |
| Sei Investments Co | 0.00% | 203,088 | $4,094,253 | $4,398,886 | +$304,633 | +7.44% | |
| Great Lakes Advisors, Llc | 0.03% | 198,004 | $3,991,760 | $4,288,767 | +$297,007 | +7.44% | |
| Squarepoint Ops Llc | 0.01% | 170,651 | $3,440,324 | $3,696,301 | +$255,977 | +7.44% | |
| Elizabeth Park Capital Advisors, Ltd. | 2.58% | 166,457 | $3,355,773 | $3,605,459 | +$249,686 | +7.44% | |
| Siena Capital Partners Gp, Llc | 0.85% | 163,038 | $3,286,846 | $3,531,403 | +$244,557 | +7.44% | |
| Blair William & Co/Il | 0.01% | 162,883 | $3,283,729 | $3,528,046 | +$244,317 | +7.44% | |
| Ejf Capital Lp | 2.15% | 151,170 | $3,047,587 | $3,274,342 | +$226,755 | +7.44% | |
| Jacobs Asset Management, Llc | 1.81% | 150,000 | $3,024,000 | $3,249,000 | +$225,000 | +7.44% | |
| Arrowstreet Capital, Limited Partnership | 0.00% | 141,026 | $2,843,084 | $3,054,623 | +$211,539 | +7.44% | |
| Victory Capital Management Inc | 0.00% | 139,054 | $2,803,329 | $3,011,910 | +$208,581 | +7.44% | |
| Knights Of Columbus Asset Advisors Llc | 0.15% | 131,441 | $2,649,851 | $2,847,012 | +$197,161 | +7.44% | |
| State Of New Jersey Common Pension Fund D | 0.01% | 129,379 | $2,608,281 | $2,802,349 | +$194,068 | +7.44% | |
| Bank Of Montreal | 0.00% | 118,465 | $2,388,255 | $2,565,952 | +$177,697 | +7.44% | |
| Russell Investments Group, Ltd. | 0.00% | 111,949 | $2,256,891 | $2,424,815 | +$167,924 | +7.44% | |
| Curi Capital, Llc | 0.04% | 100,505 | $2,026,182 | $2,176,938 | +$150,756 | +7.44% | |
| Mendon Capital Advisors Corp | 0.78% | 100,000 | $2,016,000 | $2,166,000 | +$150,000 | +7.44% | |
| Swiss National Bank | 0.00% | 98,700 | $1,989,792 | $2,137,842 | +$148,050 | +7.44% | |
| Fisher Asset Management, Llc | 0.00% | 97,285 | $1,961,265 | $2,107,193 | +$145,928 | +7.44% | |
| Sara-Bay Financial | 0.57% | 94,063 | $1,896,310 | $2,037,405 | +$141,095 | +7.44% |
Frequently asked questions about OSBC
Who owns the most OSBC stock?
The largest holders of OSBC are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for OLD SECOND BANCORP INC (OSBC).
Is OSBC widely held by superinvestors?
Many widely followed stocks like OSBC appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly OSBC is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.