Security key
55955D100
- Security type / class
- Equity / COMMON STOCK
- Total 13F shares
- 131,564,487
- Total 13F value
- $1,563,696,762
- Share change
- -5,373,846
- Put/Call ratio
- 209%
- SEC-reported price per share
- $11.88
- Number of holders
- 296
- Value change
- -$91,727,321
- Number of buys
- 159
- Number of sells
- 134
- Shares outstanding
- 143,693,070
Holder snapshot
7 signals
Open additional details 1 more signal available
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q1 2026
Institutions
296
Top holders
10
MGNI full security history
Ownership snapshot
Full 13F holder table
MAGNITE, INC. SEC filings
MAGNITE, INC. company facts
Broader feeds
Ownership snapshot
Top reported holders of MGNI - MAGNITE, INC. - COMMON STOCK (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
WELLINGTON MANAGEMENT GRO...
Disclosed value leader
VANGUARD GROUP INC
Comparable rows
15/15
Latest evidence
31 Mar 2026
13F
13D/G
Lead comparable stake: 6%
13D/G row: WELLINGTON MANAGEMENT GROUP LLP
Showing 1-6 of 15 holder rows.
Quick read
WELLINGTON MANAGEMENT GROUP LLP leads the comparable SEC ownership view at 6%.
15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens WELLINGTON MANAGEMENT GROUP LLP's linked filing trail.
Comparable ownership
Top 5
WELLINGTON MANAGEMENT GROUP LLP
6%
VANGUARD PORTFOLIO MANAGEMENT LLC
5.4%
VANGUARD CAPITAL MANAGEMENT LLC
5%
Capital Research Global Investors
3.5%
VANGUARD GROUP INC
10%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| WELLINGTON MANAGEMENT GROUP LLP |
13F
13D/G
Company
|
6%
from 13D/G
|
$140,052,533
8,629,238 shares
|
— | 31 Dec 2025 |
| VANGUARD PORTFOLIO MANAGEMENT LLC |
13D/G
Vanguard Portfolio Management
|
5.4%
|
$93,256,456
7,849,870 shares
|
$0 | 31 Mar 2026 |
| VANGUARD CAPITAL MANAGEMENT LLC |
13D/G
Vanguard Capital Management
|
5%
|
$86,525,949
7,283,329 shares
|
$0 | 31 Mar 2026 |
| Capital Research Global Investors |
13F
13D/G
Company
|
3.5%
from 13D/G
|
$209,696,290
12,920,289 shares
|
— | 31 Dec 2025 |
| VANGUARD GROUP INC |
13F
Company
|
10%
|
$240,246,684
14,802,630 shares
|
— | 31 Dec 2025 |
| BlackRock, Inc. |
13F
Company
|
8.1%
|
$188,158,440
11,593,249 shares
|
— | 31 Dec 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q1 2026
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
296
Shares
131,564,487
Rows available
296
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q1 2026 vs Q1 2026 Across Filers
Q1 2026 holders
296
Q1 2026 holders
296
Holder diff
0
| Investor | Q1 2026 Shares | Q1 2026 Shares | Share Diff | Share Chg % | Q1 2026 value | Q1 2026 value | Value change | Value Chg % |
|---|