Regeneron Pharmaceuticals, Inc.
MX ˙ BMV ˙ US75886F1075
SecurityMX:REGN / Regeneron Pharmaceuticals, Inc.
InstitutionMarshall Wace, Llp
Latest Disclosed Ownership353 shares
Latest Disclosed Value $ 272,742
Marshall Wace, Llp ownership in REGN / Regeneron Pharmaceuticals, Inc.

On May 14, 2026 - Marshall Wace, Llp filed a 13F-HR form disclosing ownership of 353 shares of Regeneron Pharmaceuticals, Inc. (MX:REGN) valued at $272,742 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 478,551 shares of Regeneron Pharmaceuticals, Inc.. This represents a change in shares of -99.93% during the quarter.

Marshall Wace, Llp has a history of taking positions in derivatives of the underlying security (REGN) 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.

MX:REGN / Regeneron Pharmaceuticals, 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)
2026-05-14 2026-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 353 -478,198 -99.93 273 -99.93 0.0001
2026-02-13 2025-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 478,551 91,667 23.69 369,379 69.80 0.3363
2025-11-13 2025-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 386,884 146,975 61.26 217,533 72.71 0.2206
2025-08-13 2025-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 239,909 238,509 17,036.36 125,952 14,099.77 0.1419
2025-05-15 2025-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 1,400 -126,000 -98.90 888 -99.02 0.0011
2025-02-13 2024-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 127,400 -6,604 -4.93 90,751 -35.58 0.1091
2024-11-14 2024-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 134,004 75,131 127.62 140,870 127.66 0.1716
2024-08-14 2024-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 58,873 -141,514 -70.62 61,877 -67.92 0.0826
2024-05-15 2024-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 200,387 105,861 111.99 192,870 132.31 0.2937
2024-02-14 2023-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 94,526 -10,751 -10.21 83,021 -4.17 0.1406
2023-11-14 2023-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 105,277 -38,231 -26.64 86,639 -15.98 0.1755
2023-08-14 2023-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 143,508 52,710 58.05 103,116 38.22 0.2014
2023-05-15 2023-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 90,798 81,098 836.06 74,606 966.09 0.1585
2023-02-14 2022-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 9,700 5,595 136.30 6,998 147.45 0.0157
2022-11-14 2022-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 4,105 -47,950 -92.11 2,828 -90.81 0.0062
2022-08-15 2022-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 52,055 48,188 1,246.13 30,769 1,039.17 0.0633
2022-05-16 2022-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 3,867 -125,161 -97.00 2,701 -96.69 0.0051
2022-02-14 2021-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 129,028 25,056 24.10 81,482 29.50 0.1505
2021-11-15 2021-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 103,972 31,520 43.50 62,922 55.49 0.2613
2021-08-13 2021-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 72,452 54,384 301.00 40,467 373.41 0.1971
2021-05-17 2021-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 18,068 15,448 589.62 8,548 575.20 0.0392
2021-02-16 2020-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 2,620 2,620 -85.50 1,266 -85.19 0.0069
2020-11-16 2020-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 0 -13,270 -100.00 0 -100.00
2020-08-13 2020-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 13,270 13,270 8,277 0.0580
2020-05-15 2020-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 0 -26,276 -100.00 0 -100.00
2020-02-14 2019-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 26,276 17,461 198.08 9,866 303.35 0.0678
2019-11-14 2019-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 8,815 -112,360 -92.73 2,446 -93.55 0.0192
2019-08-14 2019-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 121,175 121,175 1,274.65 37,928 1,450.61 0.3121
2019-05-14 2019-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 0 -1,303 -100.00 0 -100.00
2019-02-14 2018-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 1,303 1,303 487 0.0050
2018-11-14 2018-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 0 -8,703 -100.00 0 -100.00
2018-08-14 2018-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 8,703 8,703 3,002 0.0449
2017-05-12 2017-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 0 -26,755 -100.00 0 -100.00
2017-02-10 2016-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 26,755 17,116 177.57 9,822 153.47 0.0646
2016-11-10 2016-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 9,639 -11,256 -53.87 3,875 -46.90 0.0276
2016-08-12 2016-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 20,895 7,675 58.06 7,297 53.14 0.0614
2016-05-13 2016-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 13,220 12,626 2,125.59 4,765 1,379.81 0.0459
2016-02-10 2015-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 594 -14,528 -96.07 322 -95.42 0.0030
2015-11-12 2015-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 15,122 15,122 2,445.79 7,034 2,084.47 0.0864
2015-08-14 2015-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 0 -647 -100.00 0 -100.00
2015-05-11 2015-03-31 13F REGENERON PHARM COMMON STOCK 75886F107 647 647 0.00 292 0.0038
2015-02-17 2014-12-31 13F REGENERON PHARM COMMON STOCK 75886F107 0 -36,583 -100.00 0 -100.00
2014-11-13 2014-09-30 13F REGENERON PHARM COMMON STOCK 75886F107 36,583 21,746 146.57 13,189 214.70 0.1903
2014-08-14 2014-06-30 13F REGENERON PHARM COMMON STOCK 75886F107 14,837 14,837 4,191 0.0617
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
(%)
2026-05-14 2026-03-31 13F REGENERON PHARM EQUITY OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2026-02-13 2025-12-31 13F REGENERON PHARM EQUITY OPTION Call 100 -92.86 77 -90.22 n/a n/a n/a
2025-11-13 2025-09-30 13F REGENERON PHARM EQUITY OPTION Call 1,400 787 n/a n/a n/a
2025-08-13 2025-06-30 13F REGENERON PHARM EQUITY OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-05-15 2025-03-31 13F REGENERON PHARM EQUITY OPTION Call 36,500 23,149 n/a n/a n/a
2022-02-14 2021-12-31 13F October 21 Calls on REGN US at 670, American EQUITY OPTION Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F October 21 Calls on REGN US at 670, American EQUITY OPTION Call 13,900 8,412 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
(%)
2026-02-13 2025-12-31 13F REGENERON PHARM EQUITY OPTION Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-11-13 2025-09-30 13F REGENERON PHARM EQUITY OPTION Put 800 450 n/a n/a n/a
2022-02-14 2021-12-31 13F October 21 Puts on REGN US at 630, American EQUITY OPTION Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-15 2021-09-30 13F October 21 Puts on REGN US at 630, American EQUITY OPTION Put 2,300 1,392 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.