Regenxbio (RGNX)
Regenxbio on one page: short interest, daily short volume, fails to deliver, planned sales, large holders, 13F holders, earnings dates and insider trades. Listed on Nasdaq, classified by the SEC as biological products, (no diagnostic substances).
10.0M
Short interest
settlement 2026-10-15
6.8
Days to cover
+0.8 days vs prior
54.7%
Short share of volume
2026-11-02
54
Fails to deliver
settlement 2026-10-06
Thu 5 Nov
Next earnings
estimated date
$949K
Insider flow, 90 days
2 buys, 0 sells
As of 2026-11-02.
Short interest
FINRA, twice a month. The newest 48 settlements in the table, 48 in the chart. JSONAs of 15 October 2026, short interest in RGNX is 10,043,670 shares, up 2,116,067 shares over the last month. Over the last 48 readings it ranged from 4,548,522 shares (31 October 2025) to 10,459,575 shares (30 June 2026). The latest reading sits at the top of that range. At the reported average volume of 1.5M shares a day that is 6.8 days to cover.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-10-15 | 10,043,670 | +4.5% | 1,482,288 | 6.78 |
| 2026-09-30 | 9,608,992 | +21.2% | 1,603,635 | 5.99 |
| 2026-09-15 | 7,927,603 | +5.7% | 1,034,298 | 7.66 |
| 2026-08-31 | 7,497,221 | -8.5% | 1,540,035 | 4.87 |
| 2026-08-14 | 8,197,515 | +13.9% | 1,055,416 | 7.77 |
| 2026-07-31 | 7,194,939 | -16.6% | 1,897,130 | 3.79 |
| 2026-07-15 | 8,626,772 | -17.5% | 2,618,877 | 3.29 |
| 2026-06-30 | 10,459,575 | +12.9% | 3,279,369 | 3.19 |
| 2026-06-15 | 9,263,377 | +11.8% | 1,331,564 | 6.96 |
| 2026-05-29 | 8,281,637 | +16.1% | 1,838,381 | 4.50 |
| 2026-05-15 | 7,135,749 | +6.6% | 2,233,461 | 3.19 |
| 2026-04-30 | 6,692,556 | -3.6% | 551,882 | 12.13 |
| 2026-04-15 | 6,943,990 | +3.5% | 549,704 | 12.63 |
| 2026-03-31 | 6,710,934 | +3.8% | 830,357 | 8.08 |
| 2026-03-13 | 6,468,047 | +1.3% | 1,135,717 | 5.70 |
| 2026-02-27 | 6,386,587 | +6.5% | 705,539 | 9.05 |
| 2026-02-13 | 5,998,350 | +23.0% | 1,074,799 | 5.58 |
| 2026-01-30 | 4,876,066 | -4.8% | 1,344,527 | 3.63 |
| 2026-01-15 | 5,123,815 | +3.1% | 743,943 | 6.89 |
| 2025-12-31 | 4,968,961 | -2.7% | 679,436 | 7.31 |
| 2025-12-15 | 5,107,325 | -5.8% | 661,080 | 7.73 |
| 2025-11-28 | 5,424,408 | +14.4% | 688,096 | 7.88 |
| 2025-11-14 | 4,741,368 | +4.2% | 577,203 | 8.21 |
| 2025-10-31 | 4,548,522 | -6.8% | 526,229 | 8.64 |
| 2025-10-15 | 4,880,756 | -2.1% | 684,848 | 7.13 |
| 2025-09-30 | 4,984,961 | -1.6% | 518,063 | 9.62 |
| 2025-09-15 | 5,066,044 | -1.4% | 445,039 | 11.38 |
| 2025-08-29 | 5,135,426 | -6.1% | 633,175 | 8.11 |
| 2025-08-15 | 5,469,959 | -0.3% | 717,702 | 7.62 |
| 2025-07-31 | 5,484,776 | -11.3% | 633,400 | 8.66 |
| 2025-07-15 | 6,179,816 | +0.8% | 548,855 | 11.26 |
| 2025-06-30 | 6,131,126 | +11.2% | 997,583 | 6.15 |
| 2025-06-13 | 5,512,274 | -8.4% | 1,262,100 | 4.37 |
| 2025-05-30 | 6,020,756 | -4.5% | 1,071,612 | 5.62 |
| 2025-05-15 | 6,303,414 | +22.0% | 1,415,163 | 4.45 |
| 2025-04-30 | 5,168,219 | -1.6% | 897,516 | 5.76 |
| 2025-04-15 | 5,250,816 | +0.6% | 1,157,020 | 4.54 |
| 2025-03-31 | 5,219,257 | -13.7% | 1,107,943 | 4.71 |
| 2025-03-14 | 6,048,547 | -3.7% | 932,276 | 6.49 |
| 2025-02-28 | 6,280,862 | +1.8% | 749,892 | 8.38 |
| 2025-02-14 | 6,168,873 | -3.7% | 705,466 | 8.74 |
| 2025-01-31 | 6,408,552 | +5.3% | 805,293 | 7.96 |
| 2025-01-15 | 6,085,987 | +0.7% | 1,533,581 | 3.97 |
| 2024-12-31 | 6,042,356 | -3.0% | 2,152,806 | 2.81 |
| 2024-12-13 | 6,229,382 | +18.4% | 1,460,036 | 4.27 |
| 2024-11-29 | 5,259,878 | +14.0% | 1,049,512 | 5.01 |
| 2024-11-15 | 4,615,030 | -6.0% | 827,488 | 5.58 |
| 2024-10-31 | 4,909,350 | -1.6% | 455,158 | 10.79 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 2 November 2026, the short share of RGNX volume is 54.7%, up 7.5 points over the last five sessions. Over the last 30 readings it ranged from 32.0% (27 October 2026) to 76.8% (23 September 2026). The latest reading is in line with the 30-session average of 54.8%, on 340K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-11-02 | 186K | 340K | 54.7% | 1,073 |
| 2026-10-30 | 167K | 396K | 42.3% | 120 |
| 2026-10-29 | 210K | 307K | 68.4% | 0 |
| 2026-10-28 | 314K | 602K | 52.2% | 0 |
| 2026-10-27 | 134K | 419K | 32.0% | 6 |
| 2026-10-26 | 222K | 471K | 47.2% | 0 |
| 2026-10-23 | 381K | 663K | 57.5% | 0 |
| 2026-10-22 | 167K | 315K | 53.0% | 30 |
| 2026-10-21 | 178K | 306K | 58.3% | 1,220 |
| 2026-10-20 | 233K | 424K | 55.1% | 48 |
| 2026-10-19 | 193K | 413K | 46.8% | 0 |
| 2026-10-16 | 259K | 406K | 63.7% | 147 |
| 2026-10-15 | 273K | 412K | 66.3% | 0 |
| 2026-10-14 | 341K | 752K | 45.4% | 0 |
| 2026-10-13 | 210K | 457K | 45.9% | 30 |
| 2026-10-12 | 481K | 920K | 52.3% | 0 |
| 2026-10-09 | 178K | 277K | 64.2% | 42 |
| 2026-10-08 | 457K | 718K | 63.7% | 0 |
| 2026-10-07 | 201K | 338K | 59.5% | 82 |
| 2026-10-06 | 276K | 494K | 56.0% | 2 |
| 2026-10-05 | 603K | 898K | 67.1% | 0 |
| 2026-10-02 | 181K | 362K | 49.9% | 963 |
| 2026-10-01 | 254K | 496K | 51.2% | 0 |
| 2026-09-30 | 307K | 484K | 63.4% | 101 |
| 2026-09-29 | 261K | 682K | 38.3% | 16 |
| 2026-09-28 | 169K | 337K | 50.3% | 11 |
| 2026-09-25 | 273K | 415K | 65.7% | 3,886 |
| 2026-09-24 | 329K | 581K | 56.7% | 200 |
| 2026-09-23 | 318K | 414K | 76.8% | 53 |
| 2026-09-22 | 200K | 500K | 40.0% | 3,400 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 6 October 2026, the fails-to-deliver balance in RGNX is 54 shares, down 24,945 shares over the last settlement date. Over the last 30 readings it ranged from 1 share (16 April 2026) to 160,960 shares (29 June 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-10-06 | 54 | $7.76 | $419 |
| 2026-09-30 | 24,999 | $7.45 | $186K |
| 2026-09-04 | 193 | $9.20 | $2K |
| 2026-08-13 | 26,308 | $10.91 | $287K |
| 2026-08-11 | 38,980 | $10.42 | $406K |
| 2026-08-07 | 25,045 | $11.28 | $283K |
| 2026-07-31 | 17,650 | $10.12 | $179K |
| 2026-07-23 | 15 | $10.20 | $153 |
| 2026-07-17 | 44 | $11.20 | $493 |
| 2026-07-10 | 139 | $15.65 | $2K |
| 2026-07-08 | 2,427 | $15.02 | $36K |
| 2026-06-30 | 43,673 | $11.83 | $517K |
| 2026-06-29 | 160,960 | $10.48 | $1.7M |
| 2026-06-26 | 125,676 | $10.24 | $1.3M |
| 2026-06-25 | 1 | $9.97 | $10 |
| 2026-06-17 | 2,545 | $6.93 | $18K |
| 2026-06-15 | 2,266 | $6.66 | $15K |
| 2026-06-12 | 40,024 | $6.28 | $251K |
| 2026-06-02 | 12,891 | $7.14 | $92K |
| 2026-05-29 | 4,043 | $6.89 | $28K |
| 2026-05-20 | 79,854 | $5.66 | $452K |
| 2026-05-19 | 1,500 | $5.65 | $8K |
| 2026-05-18 | 12,022 | $5.72 | $69K |
| 2026-05-15 | 50,989 | $6.25 | $319K |
| 2026-04-20 | 2,013 | $9.49 | $19K |
| 2026-04-16 | 1 | $9.36 | $9 |
| 2026-03-10 | 8,000 | $10.38 | $83K |
| 2026-03-04 | 5,086 | $8.69 | $44K |
| 2026-02-03 | 192 | $10.78 | $2K |
| 2026-01-12 | 2,978 | $14.59 | $43K |
Insider trades
SEC Form 4, newest first. JSONInsiders at RGNX reported 2 open-market buys worth $949K in the last 90 days and no open-market sells. Latest filing: Malzahn Craig (Chief Technology Officer) on 2026-09-01.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-09-01 | Malzahn Craig | Chief Technology Officer | Tax withholding | 234 | $9.32 | $2K | 82K |
| 2026-09-01 | Chan Mitchell | Chief Financial Officer | Tax withholding | 5K | $9.32 | $46K | 123K |
| 2026-08-27 | Ciongoli Gregory Austin | Director | Buy | 53K | $9.36 | $500K | 118K |
| 2026-08-26 | Ciongoli Gregory Austin | Director | Buy | 49K | $9.14 | $450K | 65K |
| 2026-08-25 | Ciongoli Gregory Austin | Director | Grant | 15K | $0.00 | $0 | 15K |
| 2026-08-01 | PAKOLA STEVE | Chief Medical Officer | Tax withholding | 7K | $9.69 | $72K | 206K |
| 2026-08-01 | Christmas Patrick J. | Chief Strategy & Legal Officer | Tax withholding | 5K | $9.69 | $46K | 206K |
| 2026-07-02 | PAKOLA STEVE | Chief Medical Officer | Sell | 2K | $13.64 | $29K | 213K |
| 2026-07-02 | PAKOLA STEVE | Chief Medical Officer | Exercise or conversion | 2K | $7.86 | $17K | 215K |
| 2026-07-01 | PAKOLA STEVE | Chief Medical Officer | Sell | 37K | $12.86 | $472K | 213K |
| 2026-07-01 | PAKOLA STEVE | Chief Medical Officer | Exercise or conversion | 37K | $7.86 | $289K | 250K |
| 2026-07-01 | Simpson Curran | Chief Executive Officer | Tax withholding | 7K | $13.09 | $89K | 338K |
| 2026-06-30 | Simpson Curran | Chief Executive Officer | Grant | 1K | $10.18 | $15K | 345K |
| 2026-06-29 | PAKOLA STEVE | Chief Medical Officer | Sell | 20K | $11.04 | $216K | 213K |
| 2026-05-29 | Zachary Jennifer | Director | Grant | 10K | $0.00 | $0 | 32K |
| 2026-05-29 | Tasse Daniel | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | STUMP DAVID C | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | Mills Kenneth T. | Director | Grant | 10K | $0.00 | $0 | 496K |
| 2026-05-29 | MIGAUSKY GEORGE V | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | KARABELAS ARGERIS N | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | Glucksmann Alexandra | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | Fox Allan M. | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-29 | Bennett Jean | Director | Grant | 10K | $0.00 | $0 | 29K |
| 2026-05-11 | PAKOLA STEVE | Chief Medical Officer | Sell | 15K | $11.02 | $169K | 233K |
| 2026-03-10 | PAKOLA STEVE | Chief Medical Officer | Sell | 5K | $10.35 | $53K | 248K |
| 2026-02-01 | PAKOLA STEVE | Chief Medical Officer | Tax withholding | 5K | $11.16 | $59K | 253K |
| 2026-02-01 | Christmas Patrick J. | Chief Strategy & Legal Officer | Tax withholding | 5K | $11.16 | $52K | 211K |
| 2026-01-27 | Mills Kenneth T. | Director | Tax withholding | 222K | $13.41 | $3.0M | 486K |
| 2026-01-27 | Mills Kenneth T. | Director | Exercise or conversion | 225K | $13.09 | $2.9M | 708K |
| 2026-01-06 | Simpson Curran | Chief Executive Officer | Grant | 145K | $0.00 | $0 | 342K |
| 2026-01-06 | PAKOLA STEVE | Chief Medical Officer | Grant | 66K | $0.00 | $0 | 258K |
| 2026-01-06 | Malzahn Craig | Chief Technology Officer | Grant | 66K | $0.00 | $0 | 82K |
| 2026-01-06 | Christmas Patrick J. | Chief Strategy & Legal Officer | Grant | 74K | $0.00 | $0 | 215K |
| 2026-01-06 | Chan Mitchell | Chief Financial Officer | Grant | 74K | $0.00 | $0 | 128K |
| 2026-01-02 | Simpson Curran | Chief Executive Officer | Tax withholding | 19K | $14.40 | $267K | 198K |
| 2026-01-02 | PAKOLA STEVE | Chief Medical Officer | Tax withholding | 18K | $14.40 | $263K | 192K |
| 2026-01-02 | Malzahn Craig | Chief Technology Officer | Tax withholding | 1K | $14.40 | $18K | 16K |
| 2026-01-02 | Christmas Patrick J. | Chief Strategy & Legal Officer | Tax withholding | 10K | $14.40 | $141K | 142K |
| 2025-12-31 | Simpson Curran | Chief Executive Officer | Grant | 951 | $7.00 | $7K | 343K |
| 2025-10-09 | Simpson Curran | Chief Executive Officer | Sell | 21K | $12.62 | $263K | 216K |
| 2025-09-29 | Simpson Curran | Chief Executive Officer | Sell | 8K | $10.03 | $76K | 237K |
| 2025-09-10 | Simpson Curran | Chief Executive Officer | Sell | 8K | $10.02 | $77K | 245K |
| 2025-09-01 | Malzahn Craig | Chief Technology Officer | Tax withholding | 234 | $8.93 | $2K | 18K |
| 2025-09-01 | Chan Mitchell | Chief Financial Officer | Tax withholding | 5K | $8.93 | $44K | 54K |
| 2025-08-01 | Christmas Patrick J. | Chief Strategy & Legal Officer | Tax withholding | 5K | $8.19 | $38K | 151K |
| 2025-07-01 | Simpson Curran | Chief Executive Officer | Tax withholding | 5K | $8.23 | $39K | 252K |
| 2025-05-30 | Bennett Jean | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | KARABELAS ARGERIS N | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | Glucksmann Alexandra | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | MIGAUSKY GEORGE V | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | Mills Kenneth T. | Director | Grant | 8K | $0.00 | $0 | 483K |
| 2025-05-30 | STUMP DAVID C | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | Tasse Daniel | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-30 | Zachary Jennifer | Director | Grant | 8K | $0.00 | $0 | 22K |
| 2025-05-30 | Fox Allan M. | Director | Grant | 8K | $0.00 | $0 | 19K |
| 2025-05-12 | Mills Kenneth T. | Director | Sell | 21K | $7.91 | $163K | 475K |
| 2025-05-12 | Mills Kenneth T. | Director | Exercise or conversion | 21K | $3.76 | $77K | 496K |
| 2025-03-27 | Mills Kenneth T. | Director | Exercise or conversion | 31K | $3.76 | $116K | 475K |
| 2025-02-01 | Danos Olivier | Chief Scientific Officer | Tax withholding | 5K | $8.07 | $44K | 226K |
| 2025-02-01 | PAKOLA STEVE | Chief Medical Officer | Tax withholding | 5K | $8.07 | $42K | 211K |
| 2025-02-01 | Christmas Patrick J. | Chief Legal Officer | Tax withholding | 5K | $8.07 | $38K | 156K |
| 2025-01-02 | Christmas Patrick J. | Chief Legal Officer | Tax withholding | 11K | $7.73 | $88K | 161K |
| 2025-01-02 | Simpson Curran | Chief Executive Officer | Grant | 99K | $0.00 | $0 | 257K |
| 2025-01-02 | Simpson Curran | Chief Executive Officer | Tax withholding | 12K | $7.73 | $92K | 158K |
| 2025-01-02 | Danos Olivier | Chief Scientific Officer | Tax withholding | 13K | $7.73 | $98K | 172K |
| 2025-01-02 | Danos Olivier | Chief Scientific Officer | Grant | 59K | $0.00 | $0 | 232K |
| 2025-01-02 | PAKOLA STEVE | Chief Medical Officer | Grant | 64K | $0.00 | $0 | 216K |
| 2025-01-02 | PAKOLA STEVE | Chief Medical Officer | Tax withholding | 14K | $7.73 | $107K | 152K |
| 2024-10-01 | KARABELAS ARGERIS N | Director | Sell | 10K | $10.11 | $101K | 11K |
| 2024-10-01 | KARABELAS ARGERIS N | Director | Exercise or conversion | 10K | $3.76 | $38K | 21K |
| 2024-09-16 | Chan Mitchell | Chief Financial Officer | Grant | 59K | $0.00 | $0 | 59K |
| 2024-09-03 | KARABELAS ARGERIS N | Director | Sell | 9K | $11.50 | $107K | 12K |
| 2024-09-03 | KARABELAS ARGERIS N | Director | Sell | 700 | $12.34 | $9K | 11K |
| 2024-09-03 | KARABELAS ARGERIS N | Director | Exercise or conversion | 10K | $3.76 | $38K | 21K |
| 2024-08-08 | Mills Kenneth T. | Director | Exercise or conversion | 36K | $0.85 | $31K | 444K |
| 2024-08-01 | Danos Olivier | Chief Scientific Officer | Grant | 59K | $0.00 | $0 | 185K |
| 2024-08-01 | Simpson Curran | Chief Executive Officer | Sell | 100 | $15.00 | $2K | 170K |
| 2024-08-01 | KARABELAS ARGERIS N | Director | Sell | 100 | $15.00 | $2K | 11K |
| 2024-08-01 | KARABELAS ARGERIS N | Director | Exercise or conversion | 10K | $3.76 | $38K | 21K |
| 2024-08-01 | KARABELAS ARGERIS N | Director | Exercise or conversion | 100 | $12.74 | $1K | 21K |
| 2024-08-01 | KARABELAS ARGERIS N | Director | Sell | 10K | $13.45 | $129K | 12K |
| 2024-08-01 | KARABELAS ARGERIS N | Director | Sell | 400 | $14.59 | $6K | 11K |
| 2024-08-01 | Christmas Patrick J. | Chief Legal Officer | Grant | 56K | $0.00 | $0 | 172K |
| 2024-08-01 | PAKOLA STEVE | Chief Medical Officer | Grant | 58K | $0.00 | $0 | 166K |
| 2024-07-29 | Simpson Curran | Chief Executive Officer | Sell | 10K | $15.04 | $145K | 170K |
| 2024-07-29 | KARABELAS ARGERIS N | Director | Exercise or conversion | 11K | $12.74 | $140K | 22K |
| 2024-07-29 | KARABELAS ARGERIS N | Director | Sell | 11K | $15.05 | $166K | 11K |
| 2024-07-25 | Mills Kenneth T. | Director | Sell | 15K | $13.96 | $215K | 408K |
| 2024-07-25 | Mills Kenneth T. | Director | Exercise or conversion | 15K | $3.76 | $58K | 423K |
| 2024-07-24 | Mills Kenneth T. | Director | Exercise or conversion | 12K | $3.76 | $46K | 420K |
| 2024-07-24 | Mills Kenneth T. | Director | Sell | 12K | $13.78 | $168K | 408K |
| 2024-07-17 | Mills Kenneth T. | Director | Sell | 2K | $13.77 | $30K | 408K |
| 2024-07-17 | Mills Kenneth T. | Director | Exercise or conversion | 2K | $3.76 | $8K | 410K |
| 2024-07-16 | Mills Kenneth T. | Director | Sell | 200 | $13.76 | $3K | 408K |
| 2024-07-16 | Mills Kenneth T. | Director | Exercise or conversion | 200 | $3.76 | $752 | 408K |
| 2024-07-01 | KARABELAS ARGERIS N | Director | Exercise or conversion | 10K | $3.76 | $38K | 21K |
| 2024-07-01 | KARABELAS ARGERIS N | Director | Sell | 10K | $11.27 | $113K | 11K |
| 2024-07-01 | Simpson Curran | Chief Executive Officer | Grant | 56K | $0.00 | $0 | 180K |
| 2024-06-28 | Danos Olivier | Chief Scientific Officer | Grant | 1K | $9.95 | $14K | 126K |
| 2024-05-31 | STUMP DAVID C | Director | Grant | 5K | $0.00 | $0 | 11K |
Form 4 filings are due within two business days of the trade. Insiders sell for many reasons that say nothing about the company; open-market buys are rarer.
Planned sales (Form 144)
Newest first. JSON4 Form 144 notices on file for RGNX worth $1.2M at the prices reported; 0 in the last 90 days worth $0. Latest: Stephen J. Pakola filed on 2026-07-01 to sell 43,206 shares ($518K) from 2026-07-01.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-07-01 | Stephen J. PakolaOfficer | 43K | $518K | 0.084% | 2026-07-01 | Morgan Stanley Smith Barney LLC Executive Financial Services |
| 2026-05-11 | STEPHEN PAKOLAOfficer | 35K | $368K | 0.068% | 2026-05-11 | Morgan Stanley Smith Barney LLC Executive Financial Services |
| 2026-03-10 | STEPHEN J PAKOLAOfficer | 5K | $53K | 0.010% | 2026-03-10 | Morgan Stanley Smith Barney LLC Executive Financial Services |
| 2025-10-09 | CURRAN M SIMPSONDirector, Officer | 21K | $254K | 0.041% | 2025-10-09 | Morgan Stanley Smith Barney LLC Executive Financial Services |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSON2 holders report 5% or more of RGNX in their latest filing, all on Schedule 13G (passive). The largest reported stake is JPMORGAN CHASE & CO. at 5.3% of the class (3,560,915 shares), filed 2026-10-13 for an event on 2026-09-30.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-10-13 | 13G | JPMORGAN CHASE & CO.parent holding company | 3.6M | 5.3% | 2026-09-30 |
| 2026-05-12 | 13G | STATE STREET CORPORATIONparent holding company | 2.7M | 5.3% | 2026-03-31 |
| 2026-03-27 | 13G/Ano. 10 | The Vanguard Groupinvestment adviser | 0 | 0.0% | 2026-03-13 |
| 2026-01-21 | 13G/Ano. 1 | BlackRock Portfolio Management LLCparent holding company | 2.1M | 4.1% | 2025-12-31 |
13F holders
Tracked managers holding RGNX at their latest 13F. JSON6 of the 30 tracked managers held RGNX at their latest 13F, $49.9M in total at quarter-end prices. AQR Capital Management is the largest at $16.5M (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 5 added shares and 1 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| AQR Capital Management | 2026-06-30 | 1.4M | $16.5M | 0.01% | +327K |
| D. E. Shaw & Co. | 2026-06-30 | 713K | $8.5M | 0.00% | +427K |
| Two Sigma Investments | 2026-06-30 | 670K | $8.0M | 0.01% | +115K |
| Citadel Advisors | 2026-06-30 | 669K | $8.0M | 0.00% | new |
| Millennium Management | 2026-06-30 | 481K | $5.8M | 0.00% | +196K |
| Renaissance Technologies | 2026-06-30 | 257K | $3.1M | 0.00% | -49K |
Only the 30 tracked managers on the funds hub; a 13F reports long positions in US listed stock at quarter end, 45 days late, and says nothing about shorts or positions sold since.
What this page is
Regenxbio in the regulatory record
Regulators publish company data in separate files that never sit next to each other: FINRA's twice-monthly short interest, its daily short sale volume, the SEC's fails-to-deliver counts, and each insider's Form 4. A company page puts those series for one ticker on one URL, with planned sales, large holders, 13F holders and financials beside them, so the short position, the daily flow, the settlement fails and what insiders are doing can be read together.
Each section has its own history table, a one-line summary of the latest figures and its own JSON and CSV links, and says when its source last updated.
This page follows Regenxbio (RGNX), SEC CIK 1590877, listed on Nasdaq, classified by the SEC as biological products, (no diagnostic substances). The cross-market tables live on the short interest and insider transactions hubs.
Source and updates
- Short interest
- FINRA consolidated short interestSource: FINRA.Twice a month, about eight business days after settlement. Latest 2026-10-15.JSON and CSV
- Daily short volume
- FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-11-02.JSON and CSV
- Fails to deliver
- SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-10-06.JSON and CSV
- Planned sales
- SEC EDGAR Form 144Source: SEC.New notices appear shortly after the SEC posts them; a notice is filed on or before the sale. Latest 2026-07-01.JSON and CSV
- Large holders
- SEC EDGAR Schedule 13D and 13GSource: SEC.New filings appear shortly after the SEC posts them. A 13D is due within five business days of crossing 5%; a 13G follows the passive schedule. Latest 2026-10-13.JSON and CSV
- 13F holders
- SEC EDGAR Form 13F-HRSource: SEC.Quarterly, filed within 45 days of quarter end; 30 tracked managers. Latest 2026-06-30.JSON and CSV
- Earnings dates
- SEC EDGAR 8-K filings (Item 2.02)Source: SEC.Twice a day. Reported dates come from the company's 8-K filings; the next date is marked as an estimate until the 8-K arrives. Latest 2026-08-06.JSON and CSV
- Insider trades
- SEC EDGAR Form 4Source: SEC.New filings appear shortly after the SEC posts them; they're due two business days after the trade. Latest 2026-09-01.JSON and CSV
- Company record
- EDGAR filing index for CIK 1590877Ticker, name and exchange from the SEC's company list, refreshed weekly.
- Rate limits
- 10 requests a minute without a key, 30 with a free key from a free account.
How to read it
- Read the position against the flow: rising short interest with a high daily short share is new shorting; rising short interest with a normal short share is old shorts holding on.
- Insider buys next to a large short position are rare and stand out; insider sells next to one are common and mean little.
- Fails to deliver matter relative to the float, not in absolute shares; a million failed shares in a mega cap is noise.
Analysis of what the data shows, not advice. XOOMAR does not recommend buying, selling or holding anything.
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Datasets
Frequently Asked Questions
How much of RGNX is sold short?
10,043,670 shares were held short at the 2026-10-15 settlement, 6.8 days of average volume. FINRA publishes the next count about eight business days after the 15th and the last business day of the month.
What is RGNX's daily short volume?
On 2026-11-02, 185,693 of the 339,551 RGNX shares reported to FINRA were sold short, 54.7% of the day's reported volume. Short volume is a flow for one day, not a position.
Does RGNX have fails to deliver?
The SEC's latest file shows 54 RGNX shares failed to deliver at settlement 2026-10-06. Fails are reported per settlement date and published twice a month with a lag.
Are RGNX insiders buying or selling?
Insiders at RGNX reported 2 open-market buys worth $949K in the last 90 days and no open-market sells. Latest filing: Malzahn Craig (Chief Technology Officer) on 2026-09-01.
Have RGNX insiders filed to sell?
4 Form 144 notices on file for RGNX worth $1.2M at the prices reported; 0 in the last 90 days worth $0. Latest: Stephen J. Pakola filed on 2026-07-01 to sell 43,206 shares ($518K) from 2026-07-01.
Who owns 5% or more of RGNX?
2 holders report 5% or more of RGNX in their latest filing, all on Schedule 13G (passive). The largest reported stake is JPMORGAN CHASE & CO. at 5.3% of the class (3,560,915 shares), filed 2026-10-13 for an event on 2026-09-30.
Which tracked 13F managers own RGNX?
6 of the 30 tracked 13F managers held RGNX shares at their latest filing, $49.9M in all. The largest: Cliff Asness's AQR Capital Management (1.4M shares, $16.5M), D. E. Shaw & Co. (713K shares, $8.5M), Two Sigma Investments (670K shares, $8.0M), Ken Griffin's Citadel Advisors (669K shares, $8.0M), Izzy Englander's Millennium Management (481K shares, $5.8M), Renaissance Technologies (257K shares, $3.1M).
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.