Geron (GERN)
Geron 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 pharmaceutical preparations.
74.6M
Short interest
settlement 2026-10-15
9.9
Days to cover
+2.5 days vs prior
59.6%
Short share of volume
2026-11-02
23
Fails to deliver
settlement 2026-09-23
Wed 4 Nov
Next earnings
estimated date
$0
Insider flow, 90 days
0 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 GERN is 74,608,604 shares, down 8,010,073 shares over the last month. Over the last 48 readings it ranged from 45,629,767 shares (14 March 2025) to 92,130,954 shares (15 September 2025). At the reported average volume of 7.6M shares a day that is 9.9 days to cover.
Embed this chart.The embed keeps its attribution line.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-10-15 | 74,608,604 | +1.0% | 7,555,597 | 9.87 |
| 2026-09-30 | 73,886,113 | -10.6% | 9,999,034 | 7.39 |
| 2026-09-15 | 82,618,677 | -2.9% | 12,349,152 | 6.69 |
| 2026-08-31 | 85,093,515 | +5.6% | 7,740,111 | 10.99 |
| 2026-08-14 | 80,600,696 | +4.9% | 13,868,542 | 5.81 |
| 2026-07-31 | 76,807,284 | +9.8% | 7,761,220 | 9.90 |
| 2026-07-15 | 69,921,486 | -12.8% | 10,359,402 | 6.75 |
| 2026-06-30 | 80,219,249 | +7.2% | 17,069,245 | 4.70 |
| 2026-06-15 | 74,846,440 | +4.3% | 12,711,859 | 5.89 |
| 2026-05-29 | 71,765,644 | +2.3% | 9,429,850 | 7.61 |
| 2026-05-15 | 70,153,512 | -7.3% | 18,587,089 | 3.77 |
| 2026-04-30 | 75,696,666 | -7.9% | 13,720,232 | 5.52 |
| 2026-04-15 | 82,155,104 | +7.2% | 23,028,069 | 3.57 |
| 2026-03-31 | 76,666,335 | +21.3% | 18,369,873 | 4.17 |
| 2026-03-13 | 63,223,778 | +4.3% | 18,339,043 | 3.45 |
| 2026-02-27 | 60,621,875 | -6.8% | 20,830,115 | 2.91 |
| 2026-02-13 | 65,027,742 | +11.2% | 15,111,750 | 4.30 |
| 2026-01-30 | 58,456,685 | -17.0% | 12,596,651 | 4.64 |
| 2026-01-15 | 70,452,831 | -1.1% | 9,453,151 | 7.45 |
| 2025-12-31 | 71,256,970 | -6.3% | 6,138,024 | 11.61 |
| 2025-12-15 | 76,015,555 | -1.8% | 7,413,805 | 10.25 |
| 2025-11-28 | 77,376,655 | -0.3% | 7,018,685 | 11.02 |
| 2025-11-14 | 77,603,709 | -9.0% | 11,097,819 | 6.99 |
| 2025-10-31 | 85,259,940 | -1.9% | 6,111,662 | 13.95 |
| 2025-10-15 | 86,917,382 | -3.2% | 8,282,033 | 10.49 |
| 2025-09-30 | 89,775,024 | -2.6% | 7,460,130 | 12.03 |
| 2025-09-15 | 92,130,954 | +4.1% | 6,089,206 | 15.13 |
| 2025-08-29 | 88,536,749 | +2.2% | 5,811,216 | 15.24 |
| 2025-08-15 | 86,667,584 | +12.4% | 13,230,659 | 6.55 |
| 2025-07-31 | 77,120,335 | +13.5% | 9,639,714 | 8.00 |
| 2025-07-15 | 67,960,999 | +7.9% | 8,528,797 | 7.97 |
| 2025-06-30 | 62,985,757 | -3.4% | 10,273,277 | 6.13 |
| 2025-06-13 | 65,226,271 | +1.0% | 10,314,408 | 6.32 |
| 2025-05-30 | 64,584,701 | -3.9% | 13,303,723 | 4.85 |
| 2025-05-15 | 67,190,901 | +5.2% | 12,048,943 | 5.58 |
| 2025-04-30 | 63,864,294 | +2.6% | 9,402,518 | 6.79 |
| 2025-04-15 | 62,232,854 | +3.9% | 15,019,753 | 4.14 |
| 2025-03-31 | 59,894,969 | +31.3% | 13,881,472 | 4.31 |
| 2025-03-14 | 45,629,767 | -21.9% | 16,353,059 | 2.79 |
| 2025-02-28 | 58,414,777 | -16.3% | 24,292,606 | 2.40 |
| 2025-02-14 | 69,768,105 | -6.4% | 14,308,195 | 4.88 |
| 2025-01-31 | 74,573,338 | +1.2% | 7,529,421 | 9.90 |
| 2025-01-15 | 73,708,963 | +13.3% | 13,339,644 | 5.53 |
| 2024-12-31 | 65,068,301 | +0.8% | 15,939,129 | 4.08 |
| 2024-12-13 | 64,524,457 | -2.8% | 6,061,286 | 10.65 |
| 2024-11-29 | 66,352,865 | -5.4% | 7,421,138 | 8.94 |
| 2024-11-15 | 70,125,256 | -8.0% | 12,239,318 | 5.73 |
| 2024-10-31 | 76,242,162 | -3.3% | 6,998,783 | 10.89 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 2 November 2026, the short share of GERN volume is 59.6%, up 6.5 points over the last five sessions. Over the last 30 readings it ranged from 32.1% (6 October 2026) to 73.9% (28 September 2026). The latest reading is 8.1 points above the 30-session average of 51.5%, on 8.3M shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-11-02 | 5.0M | 8.3M | 59.6% | 20,661 |
| 2026-10-30 | 4.6M | 11.7M | 39.1% | 18,142 |
| 2026-10-29 | 12.8M | 25.2M | 50.8% | 3,024,927 |
| 2026-10-28 | 22.5M | 53.6M | 42.1% | 5,765,401 |
| 2026-10-27 | 1.6M | 3.1M | 51.2% | 1,790 |
| 2026-10-26 | 2.6M | 4.8M | 53.1% | 555 |
| 2026-10-23 | 3.7M | 6.7M | 54.8% | 51,574 |
| 2026-10-22 | 1.7M | 3.5M | 49.1% | 554 |
| 2026-10-21 | 1.9M | 3.1M | 62.5% | 2,912 |
| 2026-10-20 | 703K | 1.7M | 41.8% | 0 |
| 2026-10-19 | 1.0M | 2.5M | 41.0% | 21 |
| 2026-10-16 | 922K | 1.7M | 55.3% | 0 |
| 2026-10-15 | 851K | 1.9M | 45.9% | 5,900 |
| 2026-10-14 | 1.6M | 2.7M | 61.6% | 0 |
| 2026-10-13 | 2.4M | 4.0M | 60.0% | 0 |
| 2026-10-12 | 1.0M | 2.3M | 44.5% | 1,000 |
| 2026-10-09 | 1.3M | 2.9M | 43.9% | 0 |
| 2026-10-08 | 1.7M | 3.4M | 49.8% | 0 |
| 2026-10-07 | 1.4M | 2.8M | 50.1% | 0 |
| 2026-10-06 | 890K | 2.8M | 32.1% | 100 |
| 2026-10-05 | 1.6M | 3.6M | 44.4% | 0 |
| 2026-10-02 | 7.1M | 11.0M | 64.9% | 0 |
| 2026-10-01 | 3.8M | 6.1M | 62.3% | 0 |
| 2026-09-30 | 2.7M | 4.7M | 57.0% | 2,924 |
| 2026-09-29 | 2.4M | 3.7M | 66.3% | 31,300 |
| 2026-09-28 | 2.3M | 3.2M | 73.9% | 0 |
| 2026-09-25 | 1.1M | 2.0M | 53.6% | 0 |
| 2026-09-24 | 1.7M | 3.4M | 49.6% | 0 |
| 2026-09-23 | 2.8M | 6.7M | 41.2% | 17,346 |
| 2026-09-22 | 1.1M | 2.5M | 44.2% | 0 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 23 September 2026, the fails-to-deliver balance in GERN is 23 shares, down 27 shares over the last settlement date. Over the last 30 readings it ranged from 2 shares (9 July 2026) to 1,968,516 shares (2 March 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-09-23 | 23 | $1.31 | $30 |
| 2026-09-22 | 50 | $1.30 | $65 |
| 2026-09-08 | 191,330 | $1.57 | $300K |
| 2026-09-02 | 344 | $1.48 | $509 |
| 2026-09-01 | 336,522 | $1.49 | $501K |
| 2026-08-20 | 318 | $1.59 | $506 |
| 2026-08-19 | 36 | $1.53 | $55 |
| 2026-08-17 | 45,559 | $1.47 | $67K |
| 2026-08-06 | 28,858 | $1.63 | $47K |
| 2026-08-04 | 666,362 | $1.28 | $853K |
| 2026-07-16 | 580 | $1.42 | $824 |
| 2026-07-09 | 2 | $1.56 | $3 |
| 2026-07-06 | 1,800 | $1.36 | $2K |
| 2026-06-30 | 669 | $1.30 | $870 |
| 2026-06-24 | 753 | $1.35 | $1K |
| 2026-06-15 | 4,523 | $1.15 | $5K |
| 2026-06-08 | 145,802 | $1.17 | $171K |
| 2026-05-05 | 6,813 | $1.57 | $11K |
| 2026-05-01 | 2,554 | $1.54 | $4K |
| 2026-04-20 | 7,800 | $1.68 | $13K |
| 2026-04-07 | 765 | $1.75 | $1K |
| 2026-03-24 | 84 | $1.54 | $129 |
| 2026-03-17 | 1,115 | $1.65 | $2K |
| 2026-03-03 | 1,390 | $1.55 | $2K |
| 2026-03-02 | 1,968,516 | $1.68 | $3.3M |
| 2026-02-23 | 4,594 | $1.88 | $9K |
| 2026-02-12 | 3,901 | $1.61 | $6K |
| 2026-01-30 | 812 | $1.37 | $1K |
| 2026-01-27 | 151 | $1.37 | $207 |
| 2025-12-22 | 2,093 | $1.33 | $3K |
Insider trades
SEC Form 4, newest first. JSONNo open-market insider trades were reported for GERN in the last 90 days. The most recent filings are listed below. Latest filing: Spiegel Robert J. (Director) on 2026-09-30.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2026-09-30 | Spiegel Robert J. | Director | Grant | 6K | $1.23 | $8K | 212K |
| 2026-06-30 | Spiegel Robert J. | Director | Grant | 6K | $1.28 | $8K | 206K |
| 2026-03-31 | Spiegel Robert J. | Director | Grant | 5K | $1.49 | $8K | 200K |
| 2026-02-18 | ROBERTSON MICHELLE | EVP, CHIEF FINANCIAL OFFICER | Sell | 10K | $1.94 | $19K | 18K |
| 2026-02-18 | ROBERTSON MICHELLE | EVP, CHIEF FINANCIAL OFFICER | Exercise or conversion | 28K | $0.00 | $0 | 28K |
| 2025-12-31 | Spiegel Robert J. | Director | Grant | 6K | $1.32 | $8K | 194K |
| 2025-09-30 | Spiegel Robert J. | Director | Grant | 6K | $1.37 | $8K | 189K |
| 2025-06-30 | Spiegel Robert J. | Director | Grant | 6K | $1.41 | $8K | 183K |
| 2025-05-09 | LAWLIS V BRYAN | Director | Buy | 13K | $1.18 | $16K | 13K |
| 2025-03-31 | Spiegel Robert J. | Director | Grant | 5K | $1.59 | $8K | 177K |
| 2025-02-27 | Ziegler James | EVP, Chief Commercial Officer | Buy | 100K | $1.60 | $160K | 100K |
| 2025-02-27 | SCARLETT JOHN A | Chairman, President and CEO | Buy | 13K | $1.77 | $22K | 13K |
| 2025-02-27 | Samuels Scott Alan | EVP, Chief Legal Officer | Buy | 15K | $1.61 | $24K | 27K |
| 2024-12-31 | Spiegel Robert J. | Director | Grant | 2K | $3.54 | $8K | 172K |
| 2024-12-31 | Spiegel Robert J. | Director | Grant | 2K | $0.00 | $0 | 172K |
| 2024-09-30 | Spiegel Robert J. | Director | Grant | 2K | $4.54 | $8K | 170K |
| 2024-09-30 | Spiegel Robert J. | Director | Grant | 2K | $0.00 | $0 | 170K |
| 2024-07-08 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Exercise or conversion | 674K | $1.72 | $1.2M | 674K |
| 2024-07-08 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Sell | 674K | $4.56 | $3.1M | 0 |
| 2024-06-28 | Spiegel Robert J. | Director | Grant | 2K | $4.24 | $8K | 168K |
| 2024-06-28 | Spiegel Robert J. | Director | Grant | 2K | $0.00 | $0 | 168K |
| 2024-06-10 | Kapur Anil | EVP, Corp Strategy & CCO | Sell | 422K | $4.65 | $2.0M | 0 |
| 2024-06-10 | Kapur Anil | EVP, Corp Strategy & CCO | Exercise or conversion | 422K | $1.06 | $447K | 422K |
| 2024-06-10 | Feller Faye | EVP, Chief Medical Officer | Exercise or conversion | 20K | $1.06 | $21K | 20K |
| 2024-06-10 | Feller Faye | EVP, Chief Medical Officer | Exercise or conversion | 113K | $1.06 | $119K | 113K |
| 2024-06-10 | Feller Faye | EVP, Chief Medical Officer | Sell | 288K | $4.63 | $1.3M | 0 |
| 2024-06-10 | Feller Faye | EVP, Chief Medical Officer | Exercise or conversion | 155K | $1.30 | $202K | 155K |
| 2024-06-04 | SCARLETT JOHN A | Chairman, President and CEO | Exercise or conversion | 600K | $2.54 | $1.5M | 600K |
| 2024-06-04 | SCARLETT JOHN A | Chairman, President and CEO | Sell | 600K | $4.00 | $2.4M | 600K |
| 2024-05-15 | LAWLIS V BRYAN | Director | Exercise or conversion | 35K | $1.94 | $68K | 35K |
| 2024-05-15 | LAWLIS V BRYAN | Director | Sell | 35K | $3.75 | $131K | 0 |
| 2024-03-29 | Spiegel Robert J. | Director | Grant | 2K | $3.30 | $8K | 167K |
| 2024-03-29 | Spiegel Robert J. | Director | Grant | 2K | $0.00 | $0 | 167K |
| 2023-12-29 | Aggarwal Gaurav | Director | Grant | 2K | $0.00 | $0 | 2K |
| 2023-12-29 | Molineaux Susan | Director | Grant | 6K | $0.00 | $0 | 131K |
| 2023-12-29 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 164K |
| 2023-09-29 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 161K |
| 2023-09-29 | Molineaux Susan | Director | Grant | 6K | $0.00 | $0 | 124K |
| 2023-08-24 | O'Farrell Elizabeth G. | Director | Buy | 7K | $2.28 | $15K | 26K |
| 2023-08-24 | O'Farrell Elizabeth G. | Director | Buy | 7K | $2.28 | $15K | 7K |
| 2023-06-30 | Kapur Anil | EVP, Corp Strategy & CCO | Grant | 8K | $2.04 | $15K | 61K |
| 2023-06-30 | Spiegel Robert J. | Director | Grant | 2K | $0.00 | $0 | 157K |
| 2023-06-30 | Molineaux Susan | Director | Grant | 4K | $0.00 | $0 | 118K |
| 2023-05-11 | LAWLIS V BRYAN | Director | Exercise or conversion | 35K | $1.10 | $39K | 35K |
| 2023-05-11 | LAWLIS V BRYAN | Director | Sell | 35K | $3.00 | $105K | 0 |
| 2023-05-01 | Molineaux Susan | Director | Exercise or conversion | 35K | $1.10 | $39K | 35K |
| 2023-05-01 | Molineaux Susan | Director | Sell | 35K | $2.48 | $87K | 0 |
| 2023-03-31 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 155K |
| 2023-03-31 | Molineaux Susan | Director | Grant | 6K | $0.00 | $0 | 114K |
| 2023-02-10 | SCARLETT JOHN A | Chairman, President and CEO | Sell | 447K | $3.00 | $1.3M | 0 |
| 2023-02-10 | SCARLETT JOHN A | Chairman, President and CEO | Exercise or conversion | 447K | $1.50 | $670K | 447K |
| 2023-02-09 | SCARLETT JOHN A | Chairman, President and CEO | Exercise or conversion | 447K | $1.50 | $670K | 447K |
| 2023-02-09 | SCARLETT JOHN A | Chairman, President and CEO | Sell | 447K | $3.03 | $1.4M | 0 |
| 2023-02-09 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Sell | 235K | $3.03 | $711K | 0 |
| 2023-02-09 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Exercise or conversion | 150K | $1.51 | $227K | 385K |
| 2023-02-09 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Sell | 150K | $3.03 | $455K | 235K |
| 2023-02-08 | SCARLETT JOHN A | Chairman, President and CEO | Exercise or conversion | 447K | $1.50 | $670K | 447K |
| 2023-02-08 | SCARLETT JOHN A | Chairman, President and CEO | Sell | 447K | $3.08 | $1.4M | 0 |
| 2023-02-08 | Bloom Olivia Kyusuk | EVP, Chief Financial Officer | Sell | 400K | $3.08 | $1.2M | 75K |
| 2023-02-08 | Bloom Olivia Kyusuk | EVP, Chief Financial Officer | Exercise or conversion | 400K | $1.51 | $604K | 475K |
| 2023-01-13 | EASTHAM KARIN | Director | Exercise or conversion | 35K | $1.10 | $39K | 109K |
| 2022-12-30 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 152K |
| 2022-12-30 | Kapur Anil | EVP, Corp Strategy & CCO | Grant | 6K | $1.11 | $7K | 53K |
| 2022-09-30 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 149K |
| 2022-09-12 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Exercise or conversion | 233K | $1.70 | $396K | 235K |
| 2022-09-12 | GRETHLEIN ANDREW J | EVP, Chief Operating Officer | Exercise or conversion | 2K | $1.70 | $3K | 2K |
| 2022-06-30 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 146K |
| 2022-06-30 | Kapur Anil | EVP, Corp Strategy & CCO | Grant | 13K | $1.11 | $14K | 47K |
| 2022-04-20 | EASTHAM KARIN | Director | Exercise or conversion | 35K | $1.41 | $49K | 74K |
| 2022-03-31 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 141K |
| 2021-12-31 | Spiegel Robert J. | Director | Grant | 6K | $0.00 | $0 | 136K |
| 2021-09-30 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 130K |
| 2021-06-30 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 125K |
| 2021-03-31 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 119K |
| 2020-12-31 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 115K |
| 2020-09-30 | Spiegel Robert J. | Director | Grant | 4K | $0.00 | $0 | 110K |
| 2020-08-21 | O'Farrell Elizabeth G. | Director | Buy | 17K | $1.73 | $30K | 20K |
| 2020-06-30 | Spiegel Robert J. | Director | Grant | 3K | $0.00 | $0 | 106K |
| 2020-03-31 | Spiegel Robert J. | Director | Grant | 6K | $0.00 | $0 | 103K |
| 2020-01-10 | O'Farrell Elizabeth G. | Director | Buy | 800 | $1.35 | $1K | 800 |
| 2020-01-10 | O'Farrell Elizabeth G. | Director | Buy | 2K | $1.34 | $3K | 2K |
| 2019-12-31 | Spiegel Robert J. | Director | Grant | 5K | $0.00 | $0 | 97K |
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. JSON1 Form 144 notice on file for GERN worth $27K at the prices reported; 0 in the last 90 days worth $0. Latest: JAMES ZIEGLER filed on 2025-12-15 to sell 20,000 shares ($27K) from 2025-12-15.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2025-12-15 | JAMES ZIEGLEROfficer | 20K | $27K | 0.003% | 2025-12-15 | Morgan Stanley Smith Barney LLC Executive Financial Services |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSON11 holders report 5% or more of GERN in their latest filing, all on Schedule 13G (passive). The largest reported stake is RA Capital Management, L.P. at 9.9% of the class (66,502,728 shares), filed 2026-08-14 for an event on 2026-06-30.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-08-14 | 13G/Ano. 6 | RA Capital Management, L.P.investment adviser, partnership | 66.5M | 9.9% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 6 | Peter Kolchinskyparent holding company, individual | 66.5M | 9.9% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 6 | Rajeev Shahparent holding company, individual | 66.5M | 9.9% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 6 | RA Capital Healthcare Fund, L.P.partnership | 66.5M | 9.9% | 2026-06-30 |
| 2026-08-07 | 13G | STATE STREET CORPORATIONparent holding company | 35.9M | 5.6% | 2026-06-30 |
| 2026-05-15 | 13G/Ano. 3 | David Kroinparent holding company, individual | 31.7M | 5.0% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 3 | Deep Track Biotechnology Master Fund, Ltd.corporation | 31.7M | 5.0% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 3 | Deep Track Capital, LPinvestment adviser, other entity | 31.7M | 5.0% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Soleus Capital Master Fund, L.P.non-US institution | 41.5M | 6.5% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Soleus Capital, LLCother entity | 41.5M | 6.5% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Soleus Capital Group, LLCother entity | 41.5M | 6.5% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Soleus Capital Management, L.P.partnership | 41.5M | 6.5% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Soleus GP, LLCother entity | 41.5M | 6.5% | 2026-03-31 |
| 2026-05-08 | 13G/Ano. 1 | Guy Levyindividual | 41.5M | 6.5% | 2026-03-31 |
| 2026-03-26 | 13G/Ano. 1 | The Vanguard Groupinvestment adviser | 0 | 0.0% | 2026-03-13 |
13F holders
Tracked managers holding GERN at their latest 13F. JSON7 of the 30 tracked managers held GERN at their latest 13F, $64.3M in total at quarter-end prices. Citadel Advisors is the largest at $37.2M (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 5 added shares and 2 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| Citadel Advisors | 2026-06-30 | 29.0M | $37.2M | 0.00% | +7.5M |
| Millennium Management | 2026-06-30 | 8.1M | $10.4M | 0.00% | +791K |
| Renaissance Technologies | 2026-06-30 | 4.6M | $5.9M | 0.01% | +2.8M |
| Two Sigma Investments | 2026-06-30 | 4.3M | $5.5M | 0.00% | +2.4M |
| Point72 Asset Management | 2026-06-30 | 4.0M | $5.2M | 0.01% | -16.4M |
| D. E. Shaw & Co. | 2026-06-30 | 124K | $159K | 0.00% | new |
| AQR Capital Management | 2026-06-30 | 56K | $71K | 0.00% | -4K |
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
Geron 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 Geron (GERN), SEC CIK 886744, listed on Nasdaq, classified by the SEC as pharmaceutical preparations. 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 2026-09-23.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 2025-12-15.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 2026-08-14.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 2026-09-30.JSON and CSV
- Company record
- EDGAR filing index for CIK 886744Ticker, 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.
Other companies the SEC classifies as pharmaceutical preparations
Other company pages
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- SUISun Communities
- SUNBSunbelt Rentals Holdings
- SWSmurfit Westrock
- SWKStanley Black & Decker
- SWKSSkyworks Solutions
- SXTCChina SXT Pharmaceuticals
- SYFSynchrony Financial
- SYKStryker
- SYNASynaptics
Datasets
Frequently Asked Questions
How much of GERN is sold short?
74,608,604 shares were held short at the 2026-10-15 settlement, 9.9 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 GERN's daily short volume?
On 2026-11-02, 4,955,553 of the 8,315,602 GERN shares reported to FINRA were sold short, 59.6% of the day's reported volume. Short volume is a flow for one day, not a position.
Does GERN have fails to deliver?
The SEC's latest file shows 23 GERN shares failed to deliver at settlement 2026-09-23. Fails are reported per settlement date and published twice a month with a lag.
Are GERN insiders buying or selling?
No open-market insider trades were reported for GERN in the last 90 days. The most recent filings are listed below. Latest filing: Spiegel Robert J. (Director) on 2026-09-30.
Have GERN insiders filed to sell?
1 Form 144 notice on file for GERN worth $27K at the prices reported; 0 in the last 90 days worth $0. Latest: JAMES ZIEGLER filed on 2025-12-15 to sell 20,000 shares ($27K) from 2025-12-15.
Who owns 5% or more of GERN?
11 holders report 5% or more of GERN in their latest filing, all on Schedule 13G (passive). The largest reported stake is RA Capital Management, L.P. at 9.9% of the class (66,502,728 shares), filed 2026-08-14 for an event on 2026-06-30.
Which tracked 13F managers own GERN?
7 of the 30 tracked 13F managers held GERN shares at their latest filing, $64.3M in all. The largest: Ken Griffin's Citadel Advisors (29.0M shares, $37.2M), Izzy Englander's Millennium Management (8.1M shares, $10.4M), Renaissance Technologies (4.6M shares, $5.9M), Two Sigma Investments (4.3M shares, $5.5M), Steve Cohen's Point72 Asset Management (4.0M shares, $5.2M), D. E. Shaw & Co. (124K shares, $159K). The table above lists all 7.
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.