William Blair & Company’s Old Second Bancorp OSBC Stock Holding History
Bought
Maintained
Sold
| Quarter | Market Value | Status | Shares |
Change in Stake | Trade Value | Portfolio Weight | Portfolio Position | |
|---|---|---|---|---|---|---|---|---|
|
2026
Q1 | $3.28M | Buy |
162,883
+8,664
| +6% | +$174K | 0.01% | 604 |
|
|
2025
Q4 | $3.01M | Sell |
154,219
-217
| -0.1% | -$4.05K | 0.01% | 640 |
|
|
2025
Q3 | $2.67M | Buy |
154,436
+136,416
| +757% | +$2.46M | 0.01% | 658 |
|
|
2025
Q2 | $320K | Buy |
18,020
+21
| +0.1% | +$342 | ﹤0.01% | 1238 |
|
|
2025
Q1 | $300K | Buy |
17,999
+17
| +0.1% | +$304 | ﹤0.01% | 1257 |
|
|
2024
Q4 | $320K | Sell |
17,982
-644
| -3% | -$11.2K | ﹤0.01% | 1262 |
|
|
2024
Q3 | $290K | Buy |
18,626
+16
| +0.1% | +$257 | ﹤0.01% | 1297 |
|
|
2024
Q2 | $276K | Buy |
18,610
+7,525
| +68% | +$106K | ﹤0.01% | 1294 |
|
|
2024
Q1 | $153K | Buy |
11,085
+3
| +0% | +$42 | ﹤0.01% | 1451 |
|
|
2023
Q4 | $171K | Buy |
11,082
+2
| +0% | +$29 | ﹤0.01% | 1424 |
|
|
2023
Q3 | $151K | Buy |
11,080
+2
| +0% | +$29 | ﹤0.01% | 1444 |
|
|
2023
Q2 | $145K | Buy |
11,078
+3
| +0% | +$38 | ﹤0.01% | 1462 |
|
|
2023
Q1 | $156K | Buy |
11,075
+2
| +0% | +$32 | ﹤0.01% | 1443 |
|
|
2022
Q4 | $178K | Buy |
11,073
+2
| +0% | +$32 | ﹤0.01% | 1393 |
|
|
2022
Q3 | $144K | Buy |
11,071
+3
| +0% | +$42 | ﹤0.01% | 1448 |
|
|
2022
Q2 | $148K | Buy |
11,068
+2
| +0% | +$29 | ﹤0.01% | 1475 |
|
|
2022
Q1 | $161K | Buy |
11,066
+2
| +0% | +$28 | ﹤0.01% | 1567 |
|
|
2021
Q4 | $139K | Buy |
11,064
+3
| +0% | +$39 | ﹤0.01% | 1644 |
|
|
2021
Q3 | $144K | Buy |
11,061
+3
| +0% | +$36 | ﹤0.01% | 1563 |
|
|
2021
Q2 | $137K | Buy |
11,058
+2
| +0% | +$27 | ﹤0.01% | 1572 |
|
|
2021
Q1 | $146K | Sell |
11,056
-25,499
| -70% | -$300K | ﹤0.01% | 1539 |
|
|
2020
Q4 | $369K | Sell |
36,555
-28,194
| -44% | -$268K | ﹤0.01% | 1178 |
|
|
2020
Q3 | $485K | Buy |
64,749
+10,739
| +20% | +$85.9K | ﹤0.01% | 977 |
|
|
2020
Q2 | $420K | Sell |
54,010
-61,404
| -53% | -$454K | ﹤0.01% | 993 |
|
|
2020
Q1 | $798K | Sell |
115,414
-13,545
| -11% | -$149K | 0.01% | 729 |
|
|
2019
Q4 | $1.74M | Sell |
128,959
-14,829
| -10% | -$185K | 0.01% | 644 |
|
|
2019
Q3 | $1.76M | Sell |
143,788
-1,921
| -1% | -$23.8K | 0.01% | 602 |
|
|
2019
Q2 | $1.86M | Sell |
145,709
-274
| -0.2% | -$3.52K | 0.01% | 591 |
|
|
2019
Q1 | $1.84M | Buy |
145,983
+1,473
| +1% | +$20.4K | 0.01% | 588 |
|
|
2018
Q4 | $1.88M | Buy |
144,510
+30,619
| +27% | +$433K | 0.01% | 533 |
|
|
2018
Q3 | $1.76M | Buy |
113,891
+20,237
| +22% | +$308K | 0.01% | 585 |
|
|
2018
Q2 | $1.35M | Buy |
93,654
+52,406
| +127% | +$766K | 0.01% | 639 |
|
|
2018
Q1 | $573K | Buy |
+41,248
| New | +$587K | ﹤0.01% | 879 |
|
|
2017
Q2 | – | Sell |
-60,916
| Closed | -$684K | – | 1658 |
|
|
2017
Q1 | $684K | Hold |
60,916
| – | – | 0.01% | 804 |
|
|
2016
Q4 | $673K | Buy |
60,916
+40,290
| +195% | +$365K | 0.01% | 743 |
|
|
2016
Q3 | $171K | Buy |
+20,626
| New | +$158K | ﹤0.01% | 1190 |
|
Other funds holding OSBC
VCM
DAM
FCM
William Blair & Company's OSBC Position: Q1 2026 in Review
William Blair & Company increased its Old Second Bancorp (OSBC) stake by 5.6% in Q1 2026, buying an estimated $174K and bringing the position to 162,883 shares worth $3.28M. The position accounts for 0.01% of the portfolio, ranked #604.
William Blair & Company first reported a position in OSBC in Q3 2016 and has held it in 36 quarters since. 188 funds tracked by Wall St. Rank hold OSBC as of Q1 2026.
- William Blair & Company held 162,883 shares of Old Second Bancorp worth $3.28M as of Q1 2026.
- William Blair & Company bought 8,664 Old Second Bancorp shares in Q1 2026, an estimated $174K.
- Old Second Bancorp made up 0.01% of William Blair & Company's portfolio in Q1 2026, its #604 holding.
- William Blair & Company first reported a position in Old Second Bancorp in Q3 2016 and has held it in 36 quarters since.
- 188 funds tracked by Wall St. Rank held Old Second Bancorp as of Q1 2026.
Based on William Blair & Company's 13F filing for Q1 2026, filed 8 May 2026.