QUANTUM CORP /DE/ — DEFA14A Filings
31 DEFA14A filings on record
This page lists all DEFA14A 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 31 DEFA14A 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 |
|---|---|---|---|---|
| DEFA14A | DEFA14A | 0000709283-25-000087 | Dec 2, 2025 | — |
| DEFA14A | DEFA14A | 0001539497-25-002831 | Oct 31, 2025 | — |
| DEFA14A | DEFA14A | 0001193125-25-212384 | Sep 23, 2025 | — |
| DEFA14A | DEFA14A | 0000709283-24-000015 | Aug 2, 2024 | — |
| DEFA14A | DEFA14A | 0001539497-24-001361 | Jul 2, 2024 | — |
| DEFA14A | DEFA14A | 0001539497-23-001494 | Aug 21, 2023 | — |
| DEFA14A | DEFA14A | 0001539497-23-001311 | Jul 27, 2023 | — |
| DEFA14A | DEFA14A | 0000709283-22-000023 | Jul 5, 2022 | — |
| DEFA14A | DEFA14A | 0000709283-21-000040 | Aug 2, 2021 | — |
| DEFA14A | DEFA14A | 0000709283-20-000006 | Jul 2, 2020 | — |
| DEFA14A | DEFA14A | 0001193125-19-287054 | Nov 7, 2019 | — |
| DEFA14A | DEFA14A | 0001628280-17-007022 | Jul 12, 2017 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-17-000680 | Mar 3, 2017 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-17-000433 | Feb 15, 2017 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-17-000341 | Feb 3, 2017 | — |
| DEFA14A | CURRENT REPORT | 0001628280-17-000396 | Jan 25, 2017 | — |
| DEFA14A | CURRENT REPORT | 0001628280-17-000210 | Jan 12, 2017 | — |
| DEFA14A | CURRENT REPORT | 0001206774-16-007473 | Nov 2, 2016 | — |
| DEFA14A | CURRENT REPORT | 0001206774-16-007245 | Sep 26, 2016 | — |
| DEFA14A | — | 0000895345-16-000487 | Jun 6, 2016 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-15-002229 | Jul 21, 2015 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-14-002251 | Jul 29, 2014 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-13-002230 | Jun 24, 2013 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-12-002830 | Jun 28, 2012 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-11-001459 | Jun 29, 2011 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY SOLICITING MATERIALS | 0001206774-10-001557 | Jul 1, 2010 | — |
| DEFA14A | DEFINITIVE ADDITIONAL MATERIALS | 0001206774-09-001326 | Jul 8, 2009 | — |
| DEFA14A | DEFINITIVE ADDITIONAL MATERIALS | 0001206774-08-001243 | Jul 8, 2008 | — |
| DEFA14A | DEFINITIVE ADDITIONAL PROXY MATERIAL | 0000891618-00-005270 | Dec 11, 2000 | — |
| DEFA14A | ADDITIONAL MATERIALS TO DEFINITIVE N&P | 0000929624-00-001428 | Oct 13, 2000 | — |
| DEFA14A | SCHEDULE 14A | 0000929624-00-001405 | Oct 4, 2000 | — |