Magnite, Inc.
US ˙ NasdaqGS ˙ US55955D1000

SecurityMGNI / Magnite, Inc.
InstitutionSquarepoint Ops LLC
Latest Disclosed Ownership300,934 shares
Latest Disclosed Value $ 3,575,096
Squarepoint Ops LLC ownership in MGNI / Magnite, Inc.

On May 15, 2026 - Squarepoint Ops LLC filed a 13F-HR form disclosing ownership of 300,934 shares of Magnite, Inc. (US:MGNI) valued at $3,575,096 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 45,438 shares of Magnite, Inc.. This represents a change in shares of 562.30% during the quarter. The current value of the position is $4,348,496 USD.

Squarepoint Ops LLC 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 1,090,400 of underlying shares valued at $12,953,952 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)
2026-05-15 2026-03-31 13F MAGNITE COM 55955D100 300,934 255,496 562.30 3,575 385.07 0.0042
2026-02-13 2025-12-31 13F MAGNITE COM 55955D100 45,438 -121,031 -72.70 737 -79.67 0.0008
2025-11-14 2025-09-30 13F MAGNITE COM 55955D100 166,469 166,469 3,626 0.0036
2025-08-27 2025-06-30 13F/A-1 MAGNITE COM 55955D100 0 -123,786 -100.00 0 -100.00
2025-08-14 2025-06-30 13F MAGNITE COM 55955D100 0 -123,786 0
2025-08-27 2025-03-31 13F/A-1 MAGNITE COM 55955D100 123,786 -189,025 -60.43 1,412 -71.64 0.0017
2025-05-15 2025-03-31 13F MAGNITE COM 55955D100 123,786 -189,025 1,412 0.0017
2025-02-14 2024-12-31 13F MAGNITE COM 55955D100 312,811 -537,716 -63.22 4,980 -57.73 0.0049
2024-11-14 2024-09-30 13F MAGNITE COM 55955D100 850,527 281,816 49.55 11,780 55.85 0.0184
2024-08-14 2024-06-30 13F MAGNITE COM 55955D100 568,711 426,095 298.77 7,558 393.02 0.0125
2024-05-15 2024-03-31 13F MAGNITE COM 55955D100 142,616 52,102 57.56 1,533 81.42 0.0026
2024-02-14 2023-12-31 13F MAGNITE COM 55955D100 90,514 -124,118 -57.83 845 -47.78 0.0016
2023-11-14 2023-09-30 13F MAGNITE COM 55955D100 214,632 -46,648 -17.85 1,618 -54.63 0.0040
2023-08-14 2023-06-30 13F MAGNITE COM 55955D100 261,280 261,280 3,566 0.0109
2021-05-17 2021-03-31 13F MAGNITE COM 55955D100 0 -13,443 -100.00 0 -100.00
2021-02-16 2020-12-31 13F MAGNITE COM 55955D100 13,443 -358,121 -96.38 413 -84.00 0.0031
2020-11-16 2020-09-30 13F MAGNITE COM 55955D100 371,564 371,564 2,581 0.0348
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
(%)
2026-05-15 2026-03-31 13F MAGNITE COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2026-02-13 2025-12-31 13F MAGNITE COM Call 12,600 -38.24 204 -54.05 n/a n/a n/a
2025-11-14 2025-09-30 13F MAGNITE COM Call 20,400 -87.96 444 -89.14 n/a n/a n/a
2025-08-27 2025-06-30 13F/A MAGNITE COM Call 169,500 -60.76 4,088 -17.06 n/a n/a n/a
2025-08-14 2025-06-30 13F MAGNITE COM Call 169,500 4,088 n/a n/a n/a
2025-08-27 2025-03-31 13F/A MAGNITE COM Call 432,000 -51.02 4,929 -64.90 n/a n/a n/a
2025-05-15 2025-03-31 13F MAGNITE COM Call 432,000 4,929 n/a n/a n/a
2025-02-14 2024-12-31 13F MAGNITE COM Call 882,000 1,158.20 14,041 1,347.53 n/a n/a n/a
2024-11-14 2024-09-30 13F MAGNITE COM Call 70,100 -55.86 971 -54.03 n/a n/a n/a
2024-08-14 2024-06-30 13F MAGNITE COM Call 158,800 -71.15 2,110 -64.33 n/a n/a n/a
2024-05-15 2024-03-31 13F MAGNITE COM Call 550,400 178.97 5,917 221.17 n/a n/a n/a
2024-02-14 2023-12-31 13F MAGNITE COM Call 197,300 50.96 1,843 87.01 n/a n/a n/a
2023-11-14 2023-09-30 13F MAGNITE COM Call 130,700 985 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
(%)
2026-05-15 2026-03-31 13F MAGNITE COM Put 1,090,400 -36.28 12,954 -53.36 n/a n/a n/a
2026-02-13 2025-12-31 13F MAGNITE COM Put 1,711,300 -2.60 27,774 -27.42 n/a n/a n/a
2025-11-14 2025-09-30 13F MAGNITE COM Put 1,757,000 -1.41 38,267 -10.97 n/a n/a n/a
2025-08-27 2025-06-30 13F/A MAGNITE COM Put 1,782,100 -1.29 42,984 108.67 n/a n/a n/a
2025-08-14 2025-06-30 13F MAGNITE COM Put 1,782,100 42,984 n/a n/a n/a
2025-08-27 2025-03-31 13F/A MAGNITE COM Put 1,805,400 -9.24 20,600 -34.95 n/a n/a n/a
2025-05-15 2025-03-31 13F MAGNITE COM Put 1,805,400 20,600 n/a n/a n/a
2025-02-14 2024-12-31 13F MAGNITE COM Put 1,989,200 83.08 31,668 110.45 n/a n/a n/a
2024-11-14 2024-09-30 13F MAGNITE COM Put 1,086,500 183.61 15,048 195.58 n/a n/a n/a
2024-08-14 2024-06-30 13F MAGNITE COM Put 383,100 304.11 5,091 399.61 n/a n/a n/a
2024-05-15 2024-03-31 13F MAGNITE COM Put 94,800 -40.68 1,019 -31.70 n/a n/a n/a
2024-02-14 2023-12-31 13F MAGNITE COM Put 159,800 145.85 1,493 204.49 n/a n/a n/a
2023-11-14 2023-09-30 13F MAGNITE COM Put 65,000 490 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.