{"filing":{"accession_number":"0000357173-26-000057","cik":"0000357173","ticker":"OSBC","company_name":"OLD SECOND BANCORP INC","form":"8-K","filing_date":"2026-10-21","report_date":"2026-10-21","primary_document":"osbc-20261021x8k.htm","primary_document_url":"https://www.sec.gov/Archives/edgar/data/357173/000035717326000057/osbc-20261021x8k.htm"},"events":[{"id":36717,"run_id":33853,"accession_number":"0000357173-26-000057","anchor_item_number":"2.02","event_type":"earnings_release","event_domain":"financial","is_material":true,"confidence":0.98,"summary":"Old Second Bancorp issued a press release on October 21, 2026, announcing third quarter 2026 financial results, including net income of $28.9 million ($0.56 per diluted share), net interest margin of 5.27%, and other key financial metrics. The disclosure is a standard quarterly earnings announcement with detailed results of operations, credit quality metrics, and capital information, attached as Exhibit 99.1.","company_name":"OLD SECOND BANCORP INC","ticker":"OSBC","filing_date":"2026-10-21","form":"8-K","submitted_at":null,"items":[{"id":41220,"accession_number":"0000357173-26-000057","item_number":"2.02","item_title":"Results of Operations and Financial Condition","event_type":"earnings_release","event_domain":"financial","is_material":true,"confidence":0.98,"reasoning":"Old Second Bancorp issued a press release on October 21, 2026, announcing third quarter 2026 financial results, including net income of $28.9 million ($0.56 per diluted share), net interest margin of 5.27%, and other key financial metrics. The disclosure is a standard quarterly earnings announcement with detailed results of operations, credit quality metrics, and capital information, attached as Exhibit 99.1.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-10-21T20:19:19.358220+00:00","company_name":"","ticker":null,"filing_date":""}]}],"classifications":[{"id":41220,"accession_number":"0000357173-26-000057","item_number":"2.02","item_title":"Results of Operations and Financial Condition","event_type":"earnings_release","event_domain":"financial","is_material":true,"confidence":0.98,"reasoning":"Old Second Bancorp issued a press release on October 21, 2026, announcing third quarter 2026 financial results, including net income of $28.9 million ($0.56 per diluted share), net interest margin of 5.27%, and other key financial metrics. The disclosure is a standard quarterly earnings announcement with detailed results of operations, credit quality metrics, and capital information, attached as Exhibit 99.1.","classifier_version":"claude-haiku-4-5-20251001+prompt-a85dd512","taxonomy_version":"v1.3","classified_at":"2026-10-21T20:19:19.358220+00:00","company_name":"OLD SECOND BANCORP INC","ticker":"OSBC","filing_date":"2026-10-21"}]}