Old Second Bancorp, Inc.
DE ˙ DB ˙ US6802771005
18,20 € ↑0,60 (3,41%)
2026-06-05
DEL PRIS
SecurityDE:OSB / Old Second Bancorp, Inc.
InstitutionCitadel Advisors Llc
ManagerKen Griffin
Latest Disclosed Ownership60,065 shares
Latest Disclosed Value $ 1,210,910
Citadel Advisors Llc ownership in OSB / Old Second Bancorp, Inc.

On May 15, 2026 - Citadel Advisors Llc filed a 13F-HR form disclosing ownership of 60,065 shares of Old Second Bancorp, Inc. (DE:OSB) valued at $1,027,112 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 67,313 shares of Old Second Bancorp, Inc.. This represents a change in shares of -10.77% during the quarter. The current value of the position is $1,093,183 USD.

Citadel Advisors Llc has a history of taking positions in derivatives of the underlying security (OSB) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

DE:OSB / Old Second Bancorp, Inc. Historical Put/Call Ratio
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 60,065 -7,248 -10.77 1,211 -7.77 0.0002
2026-02-17 2025-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 67,313 -10,275 -13.24 1,313 -2.16 0.0002
2025-11-14 2025-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 77,588 25,833 49.91 1,341 46.08 0.0002
2025-08-14 2025-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 51,755 28,938 126.83 918 142.22 0.0002
2025-05-15 2025-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 22,817 -185,912 -89.07 380 -89.79 0.0001
2025-02-14 2024-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 208,729 194,487 1,365.59 3,711 1,571.62 0.0006
2024-11-14 2024-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 14,242 -43,191 -75.20 222 -73.88 0.0000
2024-08-14 2024-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 57,433 16,602 40.66 851 50.44 0.0002
2024-05-15 2024-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 40,831 -380 -0.92 565 -11.16 0.0001
2024-02-14 2023-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 41,211 20,141 95.59 636 122.38 0.0001
2023-11-14 2023-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 21,070 21,070 287 0.0001
2023-08-14 2023-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 0 -48,279 -100.00 0 -100.00
2023-05-15 2023-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 48,279 -85,021 -63.78 679 -68.29 0.0001
2023-02-14 2022-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 133,300 133,300 2,138 0.0005
2022-11-14 2022-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 0 -90,160 -100.00 0 -100.00
2022-08-15 2022-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 90,160 11,623 14.80 1,206 5.88 0.0003
2022-05-16 2022-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 78,537 58,755 297.01 1,139 357.43 0.0002
2022-02-14 2021-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 19,782 1,452 7.92 249 3.75 0.0001
2021-11-15 2021-09-30 13F OLD SECOND BANCORP INC ILL Cmn 680277100 18,330 -14,149 -43.56 240 -40.45 0.0000
2021-08-16 2021-06-30 13F OLD SECOND BANCORP INC ILL COM 680277100 32,479 -24,312 -42.81 403 -46.27 0.0001
2021-05-21 2021-03-31 13F/A-1 OLD SECOND BANCORP INC ILL COM 680277100 56,791 -6,232 -9.89 750 17.74 0.0002
2021-05-17 2021-03-31 13F OLD SECOND BANCORP INC ILL COM 680277100 56,791 -6,232 750 0.0002
2021-02-16 2020-12-31 13F OLD SECOND BANCORP INC ILL COM 680277100 63,023 -7,993 -11.26 637 19.74 0.0002
2020-11-16 2020-09-30 13F OLD SECOND BANCORP INC ILL COM 680277100 71,016 -30,951 -30.35 532 -33.00 0.0002
2020-08-14 2020-06-30 13F OLD SECOND BANCORP INC ILL Cmn 680277100 101,967 37,294 57.67 794 77.63 0.0003
2020-05-15 2020-03-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 64,673 12,997 25.15 447 -35.78 0.0002
2020-02-14 2019-12-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 51,676 -20,118 -28.02 696 -20.73 0.0003
2019-11-14 2019-09-30 13F OLD SECOND BANCORP INC ILL Cmn 680277100 71,794 25,395 54.73 878 48.06 0.0004
2019-08-14 2019-06-30 13F OLD SECOND BANCORP INC ILL Cmn 680277100 46,399 -2,125 -4.38 593 -2.95 0.0003
2019-05-15 2019-03-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 48,524 48,524 611 0.0003
2019-02-14 2018-12-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 0 -28,670 -100.00 0 -100.00
2018-11-13 2018-09-30 13F OLD SECOND BANCORP INC ILL Cmn 680277100 28,670 28,670 443 0.0002
2018-08-14 2018-06-30 13F/A-1 OLD SECOND BANCORP INC ILL Cmn 680277100 0 -11,524 -100.00 0 -100.00
2018-05-14 2018-03-31 13F/A-1 OLD SECOND BANCORP INC ILL Cmn 680277100 11,524 -4,373 -27.51 160 -26.27 0.0001
2018-05-11 2018-03-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 11,524 -4,373 160
2018-02-09 2017-12-31 13F OLD SECOND BANCORP INC ILL Cmn 680277100 15,897 15,897 217 0.0001
2014-08-14 2014-06-30 13F OLD SECOND BANCORP Cmn 680277100 0 -13,525 -100.00 0 -100.00
2014-05-15 2014-03-31 13F OLD SECOND BANCORP Cmn 680277100 13,525 13,525 62 0.0001
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-08-14 2025-06-30 13F OLD SECOND BANCORP INC ILL COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F OLD SECOND BANCORP INC ILL COM Call 3,000 42.86 50 32.43 n/a n/a n/a
2025-02-14 2024-12-31 13F OLD SECOND BANCORP INC ILL COM Call 2,100 -48.78 37 -41.27 n/a n/a n/a
2024-11-14 2024-09-30 13F OLD SECOND BANCORP INC ILL COM Call 4,100 105.00 64 117.24 n/a n/a n/a
2024-08-14 2024-06-30 13F OLD SECOND BANCORP INC ILL COM Call 2,000 -45.95 30 -43.14 n/a n/a n/a
2024-05-15 2024-03-31 13F OLD SECOND BANCORP INC ILL COM Call 3,700 5.71 51 -5.56 n/a n/a n/a
2024-02-14 2023-12-31 13F OLD SECOND BANCORP INC ILL COM Call 3,500 -27.08 54 -16.92 n/a n/a n/a
2023-11-14 2023-09-30 13F OLD SECOND BANCORP INC ILL COM Call 4,800 65 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2025-02-14 2024-12-31 13F OLD SECOND BANCORP INC ILL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2024-11-14 2024-09-30 13F OLD SECOND BANCORP INC ILL COM Put 700 0.00 11 0.00 n/a n/a n/a
2024-08-14 2024-06-30 13F OLD SECOND BANCORP INC ILL COM Put 700 600.00 10 900.00 n/a n/a n/a
2024-05-15 2024-03-31 13F OLD SECOND BANCORP INC ILL COM Put 100 1 n/a n/a n/a
2024-02-14 2023-12-31 13F OLD SECOND BANCORP INC ILL COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-11-14 2023-09-30 13F OLD SECOND BANCORP INC ILL COM Put 1,000 14 n/a n/a n/a
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.