Regeneron Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US75886F1075

SecurityREGN / Regeneron Pharmaceuticals, Inc.
InstitutionParallel Advisors, LLC
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Parallel Advisors, LLC ownership in REGN / Regeneron Pharmaceuticals, Inc.

On June 2, 2026 - Parallel Advisors, LLC filed a 13F-HR/A form disclosing ownership of 0 shares of Regeneron Pharmaceuticals, Inc. (US:REGN) valued at $0 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 995 shares of Regeneron Pharmaceuticals, Inc.. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 USD.

Parallel Advisors, LLC 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 .

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.

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)
2026-06-02 2026-03-31 13F/A-1 REGENERON PHARMACEUTICALS Stock 75886F107 0 -995 -100.00 0 -100.00
2026-02-11 2025-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 995 94 10.43 769 51.78 0.0141
2025-11-13 2025-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 901 159 21.43 507 30.08 0.0093
2025-07-08 2025-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 742 -233 -23.90 389 -37.06 0.0078
2025-04-08 2025-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 975 -129 -11.68 618 -21.37 0.0139
2025-02-10 2024-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,104 -220 -16.62 786 -43.53 0.0177
2024-11-13 2024-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,324 73 5.84 1,392 5.86 0.0327
2024-08-08 2024-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,251 100 8.69 1,315 18.79 0.0337
2024-05-06 2024-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,151 166 16.85 1,108 28.13 0.0300
2024-02-12 2023-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 985 -628 -38.93 865 -34.89 0.0257
2024-05-20 2023-09-30 13F/A-1 REGENERON PHARMACEUTICALS Stock 75886F107 1,613 72 4.67 1,327 19.87 0.0442
2023-11-14 2023-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,613 72 1,327 0.0442
2024-05-20 2023-06-30 13F/A-1 REGENERON PHARMACEUTICALS Stock 75886F107 1,541 -9 -0.58 1,107 -13.04 0.0357
2023-08-04 2023-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,541 -9 1,107 0.0357
2024-05-20 2023-03-31 13F/A-1 REGENERON PHARMACEUTICALS Stock 75886F107 1,550 -60 -3.73 1,274 9.65 0.0429
2023-04-25 2023-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,550 -60 1,274 0.0429
2023-02-06 2022-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,610 -103 -6.01 1,162 -1.61 0.0504
2022-11-10 2022-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,713 -132 -7.15 1,180 8.16 0.0543
2022-08-01 2022-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,845 790 74.88 1,091 49.45 0.0501
2022-04-28 2022-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,055 -50 -4.52 730 4.58 0.0290
2022-01-20 2021-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 1,105 63 6.05 698 10.62 0.0259
2021-11-02 2021-09-30 13F/A-1 REGENERON PHARMACEUTICALS Stock 75886F107 1,042 441 73.38 631 87.80 0.0254
2021-08-06 2021-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 601 97 19.25 336 41.18 0.0142
2021-04-23 2021-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 504 -193 -27.69 238 -29.38 0.0112
2021-02-02 2020-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 697 -194 -21.77 337 -32.46 0.0183
2020-10-27 2020-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 891 236 36.03 499 22.30 0.0309
2020-07-16 2020-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 655 101 18.23 408 51.11 0.0266
2020-04-27 2020-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 554 203 57.83 270 104.55 0.0219
2020-01-30 2019-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 351 73 26.26 132 71.43 0.0099
2019-11-01 2019-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 278 -52 -15.76 77 -25.24 0.0066
2019-08-05 2019-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 330 -65 -16.46 103 -36.42 0.0100
2019-05-01 2019-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 395 25 6.76 162 17.39 0.0182
2019-02-05 2018-12-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 370 -99 -21.11 138 -26.98 0.0192
2018-11-01 2018-09-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 469 63 15.52 189 35.00 0.0235
2018-07-30 2018-06-30 13F REGENERON PHARMACEUTICALS Stock 75886F107 406 -57 -12.31 140 -11.95 0.0200
2018-05-08 2018-03-31 13F REGENERON PHARMACEUTICALS Stock 75886F107 463 -38 -7.58 159 -15.43 0.0248
2018-02-13 2017-12-31 13F REGENERON PHARMACEUTICALS COM Stock 75886F107 501 -125 -19.97 188 -23.58 0.0308
2017-11-15 2017-09-30 13F/A-1 REGENERON PHARMACEUTICALS COM Stock 75886F107 626 -25 -3.84 246 -23.12 0.0423
2017-08-07 2017-06-30 13F REGENERON PHARMACEUTICALS COM Stock 75886F107 651 -435 -40.06 320 -27.60 0.0603
2017-05-12 2017-03-31 13F/A-1 REGENERON PHARMACEUTICALS COM Stock 75886F107 1,086 59 5.74 442 17.24 0.0879
2017-05-12 2017-03-31 13F REGENERON PHARMACEUTICALS COM Stock 75886F107 1,086 442
2017-02-14 2016-12-31 13F REGENERON PHARMACEUTICALS COM Stock 75886F107 1,027 1,027 377 0.0885
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
(%)
2022-01-19 2021-12-31 13F REGENERON PHARMACEUTICALS Stock Call 0 -100.00 0 -100.00 n/a n/a n/a
2021-10-22 2021-09-30 13F REGENERON PHARMACEUTICALS Stock Call 601 336 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.