QUANTUM CORP /DE/ — SCHEDULE 13D/A Filings
7 SCHEDULE 13D/A filings on record
This page lists all SCHEDULE 13D/A filings submitted to the SEC by QUANTUM CORP /DE/ (QMCO), sorted by most recent first. Each row links to the full filing on EdgarLookup. QUANTUM CORP /DE/ has filed 7 SCHEDULE 13D/A documents with the SEC since 2012. To view all SEC filings by QUANTUM CORP /DE/, see the full filings list.
All
10-K
10-K/A
10-K405
10-Q
10-Q/A
144
15-12G
25-NSE
3
3/A
4
4/A
424B2
424B3
424B5
425
5
8-A12B
8-A12G
8-K
8-K/A
ARS
AW
CERT
CORRESP
D
DEF 14A
DEF 14C
DEFA14A
DEFC14A
DEFR14A
DFAN14A
EFFECT
NT 10-K
NT 10-Q
POS AM
PRE 14A
PRE 14C
PREC14A
PRER14A
PRRN14A
RW
S-1
S-1/A
S-3
S-3/A
S-3ASR
S-4
S-4/A
S-8
S-8 POS
SC 13D
SC 13D/A
SC 13G
SC 13G/A
SC TO-I
SC TO-I/A
SCHEDULE 13D
SCHEDULE 13D/A
SCHEDULE 13G/A
SD
SD/A
UPLOAD
| Form | Description | Accession Number | Filed | Period |
|---|---|---|---|---|
| SCHEDULE 13D/A | — | 0000947871-26-000026 | Jan 12, 2026 | — |
| SCHEDULE 13D/A | — | 0000947871-25-001089 | Dec 22, 2025 | — |
| SCHEDULE 13D/A | — | 0000950170-25-055369 | Apr 17, 2025 | — |
| SCHEDULE 13D/A | — | 0000950170-25-047962 | Mar 31, 2025 | — |
| SCHEDULE 13D/A | — | 0000950170-25-043427 | Mar 21, 2025 | — |
| SCHEDULE 13D/A | — | 0000902664-25-001166 | Feb 21, 2025 | — |
| SCHEDULE 13D/A | — | 0000950170-25-003093 | Jan 7, 2025 | — |