Quantum Corporation
    SEC Filings

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    All SEC filings by Quantum Corporation (QMCO) — annual and quarterly reports, current reports, registrations, proxies and ownership forms, updated in real time.

    Financials

    10-QQuarterly reportView DiffAug 10, 2026
    ARSAnnual report to shareholdersJul 29, 2026
    10-KAnnual reportView DiffJun 25, 2026
    NT 10-KNotice of late annual filingJun 15, 2026
    10-QQuarterly reportView DiffFeb 17, 2026
    10-QQuarterly reportView DiffNov 13, 2025
    ARSAnnual report to shareholdersOct 31, 2025
    10-Q/AQuarterly reportView DiffSep 23, 2025
    10-QQuarterly reportView DiffSep 11, 2025
    10-KAnnual reportView DiffAug 26, 2025

    Events

    8-KQuantum Appoints Hiral A. Patel as Chief Accounting OfficerSep 1, 2026
    8-KCurrent reportAug 14, 2026
    8-KQuantum Reports Fiscal First Quarter 2027 Financial ResultsAug 10, 2026
    8-KCurrent reportJun 25, 2026
    8-KCurrent reportJun 5, 2026
    8-KCurrent reportJun 2, 2026
    8-KQuantum Reports Fiscal Third Quarter 2026 Financial ResultsFeb 17, 2026
    8-KQuantum Appoints William H. White as Chief Financial OfficerFeb 2, 2026
    8-KQuantum Announces Preliminary Fiscal Third Quarter 2026 Financial ResultsJan 15, 2026
    8-KEntry Into a Material Definitive AgreementDec 18, 2025

    Registrations and Prospectuses

    424B3Prospectus supplementJul 27, 2026
    S-1IPO registrationView DiffJul 13, 2026
    424B3Prospectus supplementFeb 24, 2026
    S-8Registration of securities for employeesFeb 18, 2026
    S-1IPO registrationView DiffFeb 18, 2026
    424B3Prospectus supplementNov 24, 2025
    S-1IPO registrationView DiffNov 14, 2025
    424B3Prospectus supplementOct 1, 2025
    POS AMProspectus update (post-effective amendment)Sep 26, 2025
    424B3Prospectus supplementApr 29, 2025

    Proxies

    DEFA14AAdditional proxy soliciting materialsJul 29, 2026
    DEF 14ADefinitive proxyView DiffJul 29, 2026
    DEFA14AAdditional proxy soliciting materialsDec 2, 2025
    DEFA14AAdditional proxy soliciting materialsOct 31, 2025
    DEF 14ADefinitive proxyView DiffOct 31, 2025
    PRE 14APreliminary proxyView DiffOct 21, 2025
    DEFA14AAdditional proxy soliciting materialsSep 23, 2025
    DEF 14ADefinitive proxyView DiffMar 27, 2025
    PRE 14APreliminary proxyView DiffMar 17, 2025
    DEFA14AAdditional proxy soliciting materialsAug 2, 2024

    Other

    EFFECTNotice of effectivenessJul 27, 2026
    SDConflict minerals disclosureMay 29, 2026
    EFFECTNotice of effectivenessFeb 24, 2026
    EFFECTNotice of effectivenessNov 24, 2025
    EFFECTNotice of effectivenessOct 1, 2025
    SDConflict minerals disclosureMay 28, 2025
    EFFECTNotice of effectivenessApr 29, 2025
    UPLOADLetter from SECApr 24, 2025
    CORRESPCorrespondence with SECApr 24, 2025
    EFFECTNotice of effectivenessFeb 12, 2025

    Ownership

    SC 13GBeneficial ownership reportAug 14, 2026
    SC 13GBeneficial ownership reportAug 14, 2026
    SC 13GBeneficial ownership reportAug 10, 2026
    4Craythorne AnthonyAug 5, 2026
    4Nash Laura A.Jul 7, 2026
    4Meyrath HuguesJul 7, 2026
    4Fichthorn JohnJun 8, 2026
    4Dialectic Technology Spv LlcJun 8, 2026
    SC 13D/ABeneficial ownership reportJun 8, 2026
    4Laura A. NashApr 3, 2026