Magnite, Inc.
US ˙ NasdaqGS ˙ US55955D1000

SecurityMGNI / Magnite, Inc.
InstitutionD. E. Shaw & Co., Inc.
ManagerDE Shaw
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
D. E. Shaw & Co., Inc. ownership in MGNI / Magnite, Inc.

On February 17, 2026 - D. E. Shaw & Co., Inc. filed a 13F-HR form disclosing ownership of 0 shares of Magnite, Inc. (US:MGNI) valued at $0 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 14, 2025 disclosing 211,433 shares of Magnite, Inc.. The current value of the position is $0 USD.

D. E. Shaw & Co., Inc. has a history of taking positions in derivatives of the underlying security (MGNI) in the form of stock options. The firm currently holds call options representing 0 of underlying shares valued at $0 USD and put options representing 0 of underlying shares valued at $0 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MGNI / Magnite, Inc. Historical Put/Call Ratio
Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-02-17 2025-12-31 13F MAGNITE COM 55955D100 0 -100.00 0
2025-11-14 2025-09-30 13F MAGNITE COM 55955D100 211,433 179,486 561.82 4,605 498.05 0.0019
2025-08-14 2025-06-30 13F MAGNITE COM 55955D100 31,947 31,947 771 0.0005
2025-05-15 2025-03-31 13F MAGNITE COM 55955D100 0 -45,187 -100.00 0 -100.00
2025-02-14 2024-12-31 13F MAGNITE COM 55955D100 45,187 24,917 122.93 719 156.79 0.0005
2024-11-14 2024-09-30 13F MAGNITE COM 55955D100 20,270 -20,827 -50.68 281 -48.72 0.0002
2024-08-14 2024-06-30 13F MAGNITE COM 55955D100 41,097 13,731 50.18 546 85.71 0.0005
2024-05-15 2024-03-31 13F MAGNITE COM 55955D100 27,366 27,366 294 0.0003
2023-05-15 2023-03-31 13F MAGNITE COM 55955D100 0 -97,767 -100.00 0 -100.00
2023-02-14 2022-12-31 13F MAGNITE COM 55955D100 97,767 81,153 488.46 1,035 849.54 0.0011
2022-11-14 2022-09-30 13F MAGNITE COM 55955D100 16,614 -20,014 -54.64 109 -66.46 0.0001
2022-08-15 2022-06-30 13F MAGNITE COM 55955D100 36,628 -104,631 -74.07 325 -82.58 0.0004
2022-05-16 2022-03-31 13F MAGNITE COM 55955D100 141,259 141,259 1,866 0.0017
2021-08-16 2021-06-30 13F MAGNITE COM 55955D100 0 -99,883 -100.00 0 -100.00
2021-05-17 2021-03-31 13F MAGNITE COM 55955D100 99,883 76,738 331.55 4,156 484.53 0.0040
2021-02-16 2020-12-31 13F MAGNITE COM 55955D100 23,145 23,145 711 0.0006
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-17 2025-12-31 13F MAGNITE COM Call 0 -100.00 0 n/a n/a n/a
2025-11-14 2025-09-30 13F MAGNITE COM Call 32,700 712 n/a n/a n/a
2021-08-16 2021-06-30 13F MAGNITE COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-05-17 2021-03-31 13F MAGNITE COM Call 70,000 2,913 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-02-17 2025-12-31 13F MAGNITE COM Put 0 -100.00 0 n/a n/a n/a
2025-11-14 2025-09-30 13F MAGNITE COM Put 14,800 322 n/a n/a n/a
2022-05-16 2022-03-31 13F MAGNITE COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-14 2021-12-31 13F MAGNITE COM Put 75,800 1,327 n/a n/a n/a
2021-11-15 2021-09-30 13F MAGNITE COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-08-16 2021-06-30 13F MAGNITE COM Put 60,000 -86.52 2,030 -89.04 n/a n/a n/a
2021-05-17 2021-03-31 13F MAGNITE COM Put 445,000 18,516 n/a n/a n/a
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.