Old Second Bancorp, Inc.
US ˙ NasdaqGS ˙ US6802771005

SecurityOSBC / Old Second Bancorp, Inc.
InstitutionFmr Llc
Latest Disclosed Ownership5,842 shares
Latest Disclosed Value $ 117,776
Fmr Llc reports 31.64% increase in ownership of OSBC / Old Second Bancorp, Inc.

On May 15, 2026 - Fmr Llc filed a 13F-HR form disclosing ownership of 5,842 shares of Old Second Bancorp, Inc. (US:OSBC) valued at $117,775 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 4,438 shares of Old Second Bancorp, Inc.. This represents a change in shares of 31.64% during the quarter. The current value of the position is $120,929 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-15 2026-03-31 13F OLD SECOND BANCORP INC DEL COM 680277100 5,842 1,404 31.64 118 36.05 0.0000
2026-02-17 2025-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 4,438 -11,171 -71.57 87 -68.03 0.0000
2025-11-13 2025-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 15,609 -16,377 -51.20 270 -52.56 0.0000
2025-08-14 2025-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 31,986 8,180 34.36 567 43.18 0.0000
2025-05-12 2025-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 23,806 20,730 673.93 396 633.33 0.0000
2025-02-13 2024-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 3,076 581 23.29 55 42.11 0.0000
2024-11-13 2024-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 2,495 169 7.27 39 11.76 0.0000
2024-08-13 2024-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 2,326 1,466 170.47 34 209.09 0.0000
2024-05-13 2024-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 860 -136 -13.65 12 -26.67 0.0000
2024-02-13 2023-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 996 337 51.14 15 87.50 0.0000
2023-11-13 2023-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 659 45 7.33 9 0.00 0.0000
2023-08-11 2023-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 614 -3,310 -84.35 8 -85.45 0.0000
2023-08-11 2023-03-31 13F/A-1 OLD SECOND BANCORP INC ILL COM 680277100 3,924 -7,775 -66.46 55 -70.59 0.0000
2023-05-11 2023-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 3,924 -7,775 55 0.0000
2023-02-13 2022-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 11,699 -42 -0.36 188 22.22 0.0000
2022-11-10 2022-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 11,741 -145 -1.22 153 -3.77 0.0000
2022-08-12 2022-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 11,886 6 0.05 159 -8.09 0.0000
2022-05-13 2022-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 11,880 -3,798 -24.23 173 -12.18 0.0000
2022-02-14 2021-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 15,678 -1,076,441 -98.56 197 -98.62 0.0000
2022-02-14 2021-09-30 13F/A-1 OLD SECOND BANCORP INC ILL COM 680277100 1,092,119 -31,816 -2.83 14,263 2.34 0.0011
2021-11-15 2021-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 1,092,119 -31,816 14,263 0.0002
2021-08-13 2021-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 1,123,935 244,619 27.82 13,937 19.98 0.0011
2021-05-14 2021-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 879,316 112,280 14.64 11,616 49.94 0.0010
2021-02-08 2020-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 767,036 7,200 0.95 7,747 36.03 0.0007
2020-11-13 2020-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 759,836 -16,300 -2.10 5,695 -5.68 0.0006
2020-08-24 2020-06-30 13F/A-1 OLD SECOND BANCORP INC ILL COM 680277100 776,136 -52,900 -6.38 6,038 5.39 0.0007
2020-08-13 2020-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 776,136 -52,900 6,038 148.3360
2020-05-14 2020-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 829,036 829,036 5,729 0.0008
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.