REGENXBIO Inc.
US ˙ NasdaqGS ˙ US75901B1070

SecurityRGNX / REGENXBIO Inc.
InstitutionCitigroup Inc
Latest Disclosed Ownership25,650 shares
Latest Disclosed Value $ 214,947
Citigroup Inc ownership in RGNX / REGENXBIO Inc.

On May 11, 2026 - Citigroup Inc filed a 13F-HR form disclosing ownership of 25,650 shares of REGENXBIO Inc. (US:RGNX) valued at $214,947 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 9,259 shares of REGENXBIO Inc.. This represents a change in shares of 177.03% during the quarter. The current value of the position is $171,598 USD.

Citigroup Inc has a history of taking positions in derivatives of the underlying security (RGNX) in the form of stock options. The firm currently holds call options representing 49,500 of underlying shares valued at $414,810 USD and put options representing 49,500 of underlying shares valued at $414,810 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.

RGNX / REGENXBIO 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)
2026-05-11 2026-03-31 13F REGENXBIO COM 75901B107 25,650 16,391 177.03 215 60.90 0.0000
2026-02-13 2025-12-31 13F REGENXBIO COM 75901B107 9,259 5,026 118.73 133 232.50 0.0001
2025-11-10 2025-09-30 13F REGENXBIO COM 75901B107 4,233 -26,216 -86.10 41 -83.94 0.0000
2025-08-11 2025-06-30 13F REGENXBIO COM 75901B107 30,449 -6,701 -18.04 250 -6.04 0.0001
2025-05-12 2025-03-31 13F REGENXBIO COM 75901B107 37,150 -77,661 -67.64 266 -70.12 0.0001
2025-02-12 2024-12-31 13F REGENXBIO COM 75901B107 114,811 19,300 20.21 887 -11.39 0.0005
2024-11-12 2024-09-30 13F REGENXBIO COM 75901B107 95,511 52,603 122.59 1,002 99.40 0.0006
2024-08-12 2024-06-30 13F REGENXBIO COM 75901B107 42,908 -143,845 -77.02 502 -87.24 0.0003
2024-05-10 2024-03-31 13F REGENXBIO COM 75901B107 186,753 114,542 158.62 3,935 203.55 0.0026
2024-02-09 2023-12-31 13F REGENXBIO COM 75901B107 72,211 -29,375 -28.92 1,296 -22.49 0.0009
2023-12-06 2023-09-30 13F/A-1 REGENXBIO COM 75901B107 101,586 19,949 24.44 1,672 2.51 0.0012
2023-11-09 2023-09-30 13F REGENXBIO COM 75901B107 101,586 19,949 1,672 0.0005
2023-08-10 2023-06-30 13F REGENXBIO COM 75901B107 81,637 -42,230 -34.09 1,632 -30.36 0.0011
2023-05-11 2023-03-31 13F REGENXBIO COM 75901B107 123,867 34,856 39.16 2,342 16.06 0.0016
2023-02-09 2022-12-31 13F REGENXBIO COM 75901B107 89,011 -39,670 -30.83 2,019 -40.65 0.0016
2022-11-10 2022-09-30 13F REGENXBIO COM 75901B107 128,681 28,202 28.07 3,400 37.04 0.0024
2022-08-10 2022-06-30 13F REGENXBIO COM 75901B107 100,479 39,076 63.64 2,481 21.74 0.0018
2022-05-12 2022-03-31 13F REGENXBIO COM 75901B107 61,403 -68,195 -52.62 2,038 -51.91 0.0012
2022-02-10 2021-12-31 13F REGENXBIO COM 75901B107 129,598 -1,154 -0.88 4,238 -22.68 0.0023
2021-11-10 2021-09-30 13F REGENXBIO COM 75901B107 130,752 -11,765 -8.26 5,481 -1.01 0.0032
2021-08-10 2021-06-30 13F REGENXBIO COM 75901B107 142,517 -2,941 -2.02 5,537 11.61 0.0033
2021-05-13 2021-03-31 13F REGENXBIO COM 75901B107 145,458 54,947 60.71 4,961 20.82 0.0032
2021-02-11 2020-12-31 13F REGENXBIO COM 75901B107 90,511 -107,368 -54.26 4,106 -24.61 0.0024
2020-11-12 2020-09-30 13F REGENXBIO COM 75901B107 197,879 155,091 362.46 5,446 245.56 0.0036
2020-08-12 2020-06-30 13F REGENXBIO COM 75901B107 42,788 1,492 3.61 1,576 17.88 0.0012
2020-05-12 2020-03-31 13F REGENXBIO COM 75901B107 41,296 -10,571 -20.38 1,337 -37.08 0.0012
2020-02-12 2019-12-31 13F REGENXBIO COM 75901B107 51,867 -49,575 -48.87 2,125 -41.17 0.0015
2019-11-08 2019-09-30 13F REGENXBIO COM 75901B107 101,442 10,440 11.47 3,612 -22.74 0.0029
2019-08-12 2019-06-30 13F REGENXBIO COM 75901B107 91,002 65,799 261.08 4,675 223.53 0.0038
2019-05-13 2019-03-31 13F REGENXBIO COM 75901B107 25,203 -136,710 -84.43 1,445 -78.72 0.0014
2019-02-12 2018-12-31 13F REGENXBIO COM 75901B107 161,913 73,730 83.61 6,792 2.03 0.0069
2018-11-13 2018-09-30 13F REGENXBIO COM 75901B107 88,183 -99,629 -53.05 6,657 -50.60 0.0059
2018-08-10 2018-06-30 13F REGENXBIO COM 75901B107 187,812 90,699 93.40 13,476 364.85 0.0124
2018-05-11 2018-03-31 13F REGENXBIO COM 75901B107 97,113 16,846 20.99 2,899 8.62 0.0024
2018-02-12 2017-12-31 13F REGENXBIO COM 75901B107 80,267 24,285 43.38 2,669 44.66 0.0021
2017-11-13 2017-09-30 13F REGENXBIO COM 75901B107 55,982 26,634 90.75 1,845 218.10 0.0015
2017-08-11 2017-06-30 13F REGENXBIO COM 75901B107 29,348 26,780 1,042.83 580 1,083.67 0.0005
2017-05-12 2017-03-31 13F REGENXBIO COM 75901B107 2,568 -19,626 -88.43 49 -88.11 0.0000
2017-02-10 2016-12-31 13F REGENXBIO COM 75901B107 22,194 20,557 1,255.77 412 1,691.30 0.0004
2016-11-10 2016-09-30 13F REGENXBIO COM 75901B107 1,637 -379 -18.80 23 43.75 0.0000
2016-08-12 2016-06-30 13F REGENXBIO COM 75901B107 2,016 -3,917 -66.02 16 -75.00 0.0000
2016-05-13 2016-03-31 13F REGENXBIO COM 75901B107 5,933 3,748 171.53 64 77.78 0.0001
2016-02-12 2015-12-31 13F REGENXBIO COM 75901B107 2,185 2,185 36 0.0000
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
(%)
2026-05-11 2026-03-31 13F REGENXBIO COM Call 49,500 415 n/a n/a n/a
2025-05-12 2025-03-31 13F REGENXBIO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-12 2024-12-31 13F REGENXBIO COM Call 24,900 -0.40 192 -26.72 n/a n/a n/a
2024-11-12 2024-09-30 13F REGENXBIO COM Call 25,000 262 n/a n/a n/a
2024-02-09 2023-12-31 13F REGENXBIO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2023-12-06 2023-09-30 13F/A REGENXBIO COM Call 50,000 100.80 823 65.59 n/a n/a n/a
2023-11-09 2023-09-30 13F REGENXBIO COM Call 50,000 823 n/a n/a n/a
2023-08-10 2023-06-30 13F REGENXBIO COM Call 24,900 498 n/a n/a n/a
2019-11-08 2019-09-30 13F REGENXBIO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2019-08-12 2019-06-30 13F REGENXBIO COM Call 600 -70.00 31 -73.04 n/a n/a n/a
2019-05-13 2019-03-31 13F REGENXBIO COM Call 2,000 115 n/a n/a n/a
2019-02-12 2018-12-31 13F REGENXBIO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2018-11-13 2018-09-30 13F REGENXBIO COM Call 6,400 483 n/a n/a n/a
2018-02-12 2017-12-31 13F REGENXBIO COM Call 0 -100.00 0 -100.00 n/a n/a n/a
2017-11-13 2017-09-30 13F REGENXBIO COM Call 12,600 415 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
(%)
2026-05-11 2026-03-31 13F REGENXBIO COM Put 49,500 415 n/a n/a n/a
2025-05-12 2025-03-31 13F REGENXBIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2025-02-12 2024-12-31 13F REGENXBIO COM Put 24,900 -0.40 192 -26.72 n/a n/a n/a
2024-11-12 2024-09-30 13F REGENXBIO COM Put 25,000 262 n/a n/a n/a
2024-02-09 2023-12-31 13F REGENXBIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2023-12-06 2023-09-30 13F/A REGENXBIO COM Put 50,000 100.80 823 65.59 n/a n/a n/a
2023-11-09 2023-09-30 13F REGENXBIO COM Put 50,000 823 n/a n/a n/a
2023-08-10 2023-06-30 13F REGENXBIO COM Put 24,900 498 n/a n/a n/a
2019-11-08 2019-09-30 13F REGENXBIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2019-08-12 2019-06-30 13F REGENXBIO COM Put 3,800 -79.79 195 -81.89 n/a n/a n/a
2019-05-13 2019-03-31 13F REGENXBIO COM Put 18,800 -36.27 1,077 -13.00 n/a n/a n/a
2019-02-12 2018-12-31 13F REGENXBIO COM Put 29,500 1,238 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.