LB Pharmaceuticals (LBRX)
LB Pharmaceuticals 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.
5.6M
Short interest
settlement 2026-10-15
12.1
Days to cover
-2.4 days vs prior
60.6%
Short share of volume
2026-11-02
710
Fails to deliver
settlement 2026-09-18
Thu 5 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 27 settlements in the table, 27 in the chart. JSONAs of 15 October 2026, short interest in LBRX is 5,564,315 shares, down 52,867 shares over the last month. Over the last 27 readings it ranged from 126,558 shares (15 September 2025) to 6,010,646 shares (30 September 2026). The latest reading sits at the top of that range. At the reported average volume of 458K shares a day that is 12.1 days to cover.
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| Settlement | Shares short | Change | Avg daily volume | Days to cover |
|---|---|---|---|---|
| 2026-10-15 | 5,564,315 | -7.4% | 458,488 | 12.14 |
| 2026-09-30 | 6,010,646 | +7.0% | 414,301 | 14.51 |
| 2026-09-15 | 5,617,182 | +6.4% | 261,863 | 21.45 |
| 2026-08-31 | 5,278,529 | +2.4% | 265,345 | 19.89 |
| 2026-08-14 | 5,156,413 | +8.6% | 416,373 | 12.38 |
| 2026-07-31 | 4,746,857 | +11.4% | 370,847 | 12.80 |
| 2026-07-15 | 4,260,793 | -6.4% | 242,211 | 17.59 |
| 2026-06-30 | 4,550,288 | +5.8% | 465,331 | 9.78 |
| 2026-06-15 | 4,302,626 | +7.2% | 173,854 | 24.75 |
| 2026-05-29 | 4,015,182 | -0.1% | 184,107 | 21.81 |
| 2026-05-15 | 4,018,158 | +5.8% | 128,873 | 31.18 |
| 2026-04-30 | 3,799,720 | +22.2% | 257,232 | 14.77 |
| 2026-04-15 | 3,110,447 | +18.6% | 353,456 | 8.80 |
| 2026-03-31 | 2,621,739 | -3.4% | 275,131 | 9.53 |
| 2026-03-13 | 2,713,021 | +3.7% | 217,473 | 12.48 |
| 2026-02-27 | 2,615,602 | +18.9% | 213,128 | 12.27 |
| 2026-02-13 | 2,199,776 | +21.9% | 178,137 | 12.35 |
| 2026-01-30 | 1,804,088 | +0.8% | 178,270 | 10.12 |
| 2026-01-15 | 1,790,725 | -2.4% | 258,049 | 6.94 |
| 2025-12-31 | 1,833,981 | +294.8% | 678,833 | 2.70 |
| 2025-12-15 | 464,576 | +91.5% | 272,216 | 1.71 |
| 2025-11-28 | 242,536 | -2.9% | 138,444 | 1.75 |
| 2025-11-14 | 249,832 | +12.0% | 109,087 | 2.29 |
| 2025-10-31 | 223,012 | -19.3% | 77,882 | 2.86 |
| 2025-10-15 | 276,214 | +39.1% | 238,770 | 1.16 |
| 2025-09-30 | 198,541 | +56.9% | 147,729 | 1.34 |
| 2025-09-15 | 126,558 | +100.0% | 474,331 | 1.00 |
Daily short volume
FINRA Reg SHO, the last 30 sessions. JSONAs of 2 November 2026, the short share of LBRX volume is 60.6%, down 12.5 points over the last five sessions. Over the last 30 readings it ranged from 31.2% (23 September 2026) to 87.3% (16 October 2026). The latest reading is 6.9 points below the 30-session average of 67.5%, on 215K shares reported.
| Date | Short volume | Total volume | Short share | Exempt |
|---|---|---|---|---|
| 2026-11-02 | 130K | 215K | 60.6% | 0 |
| 2026-10-30 | 120K | 216K | 55.4% | 3 |
| 2026-10-29 | 116K | 139K | 83.6% | 0 |
| 2026-10-28 | 65K | 81K | 80.0% | 0 |
| 2026-10-27 | 68K | 105K | 65.0% | 0 |
| 2026-10-26 | 86K | 117K | 73.2% | 0 |
| 2026-10-23 | 49K | 69K | 69.8% | 0 |
| 2026-10-22 | 68K | 101K | 67.6% | 0 |
| 2026-10-21 | 99K | 120K | 82.2% | 200 |
| 2026-10-20 | 108K | 158K | 68.6% | 0 |
| 2026-10-19 | 175K | 236K | 74.2% | 0 |
| 2026-10-16 | 247K | 283K | 87.3% | 0 |
| 2026-10-15 | 352K | 452K | 77.9% | 0 |
| 2026-10-14 | 67K | 113K | 59.6% | 0 |
| 2026-10-13 | 73K | 101K | 72.2% | 0 |
| 2026-10-12 | 114K | 165K | 69.0% | 0 |
| 2026-10-09 | 156K | 245K | 63.5% | 9,771 |
| 2026-10-08 | 150K | 191K | 78.6% | 0 |
| 2026-10-07 | 168K | 197K | 85.2% | 0 |
| 2026-10-06 | 133K | 166K | 79.9% | 68,140 |
| 2026-10-05 | 94K | 184K | 51.4% | 0 |
| 2026-10-02 | 131K | 165K | 79.3% | 0 |
| 2026-10-01 | 47K | 98K | 47.6% | 0 |
| 2026-09-30 | 98K | 130K | 75.6% | 0 |
| 2026-09-29 | 93K | 266K | 35.1% | 0 |
| 2026-09-28 | 194K | 228K | 85.3% | 0 |
| 2026-09-25 | 96K | 181K | 53.2% | 0 |
| 2026-09-24 | 76K | 165K | 46.0% | 4,612 |
| 2026-09-23 | 72K | 230K | 31.2% | 600 |
| 2026-09-22 | 53K | 79K | 67.2% | 0 |
Fails to deliver
SEC, the last 30 settlement dates with a fail. JSONAs of 18 September 2026, the fails-to-deliver balance in LBRX is 710 shares, up 184 shares over the last settlement date. Over the last 30 readings it ranged from 4 shares (4 August 2026) to 40,000 shares (4 September 2026). The latest reading sits at the bottom of that range.
| Settlement | Shares failed | Price | Value |
|---|---|---|---|
| 2026-09-18 | 710 | $42.14 | $30K |
| 2026-09-17 | 526 | $42.57 | $22K |
| 2026-09-08 | 27,819 | $49.34 | $1.4M |
| 2026-09-04 | 40,000 | $47.52 | $1.9M |
| 2026-08-18 | 2,192 | $46.23 | $101K |
| 2026-08-17 | 2,379 | $47.78 | $114K |
| 2026-08-11 | 261 | $45.85 | $12K |
| 2026-08-04 | 4 | $42.84 | $171 |
| 2026-07-07 | 2,408 | $33.41 | $80K |
| 2026-07-01 | 362 | $32.46 | $12K |
| 2026-06-29 | 2,286 | $31.92 | $73K |
| 2026-06-26 | 45 | $31.00 | $1K |
| 2026-06-15 | 37 | $28.42 | $1K |
| 2026-06-12 | 9,294 | $28.54 | $265K |
| 2026-05-28 | 13 | $27.80 | $361 |
| 2026-05-26 | 19,900 | $28.12 | $560K |
| 2026-05-21 | 200 | $28.03 | $6K |
| 2026-05-05 | 29 | $31.83 | $923 |
| 2026-04-28 | 199 | $31.81 | $6K |
| 2026-04-27 | 301 | $30.73 | $9K |
| 2026-04-24 | 798 | $30.78 | $25K |
| 2026-04-21 | 433 | $31.67 | $14K |
| 2026-04-17 | 4,330 | $28.28 | $122K |
| 2026-04-16 | 97 | $29.12 | $3K |
| 2026-04-15 | 67 | $26.57 | $2K |
| 2026-04-13 | 55 | $24.34 | $1K |
| 2026-04-10 | 410 | $26.29 | $11K |
| 2026-04-09 | 346 | $25.98 | $9K |
| 2026-04-07 | 53 | $26.94 | $1K |
| 2026-04-02 | 66 | $24.81 | $2K |
Insider trades
SEC Form 4, newest first. JSONNo open-market insider trades were reported for LBRX in the last 90 days. The most recent filings are listed below. Latest filing: Vida Ventures GP III, L.L.C. (TenPercentOwner) on 2025-09-12.
| Date | Insider | Title | Type | Shares | Price | Value | Owned after |
|---|---|---|---|---|---|---|---|
| 2025-09-12 | Vida Ventures GP III, L.L.C. | TenPercentOwner | Conversion | 1K | price not stated in the filing | not stated | 1K |
| 2025-09-12 | Vida Ventures GP III, L.L.C. | TenPercentOwner | Conversion | 548K | price not stated in the filing | not stated | 548K |
| 2025-09-12 | Vida Ventures GP III, L.L.C. | TenPercentOwner | Buy | 767 | $15.00 | $12K | 2K |
| 2025-09-12 | Vida Ventures GP III, L.L.C. | TenPercentOwner | Buy | 333K | $15.00 | $5.0M | 880K |
| 2025-09-12 | Nussbaum Ran | Director | Buy | 1.0M | $15.00 | $15.0M | 1.4M |
| 2025-09-12 | Nussbaum Ran | Director | Conversion | 412K | price not stated in the filing | not stated | 412K |
| 2025-09-12 | Pontifax Management 4 G.P. (2015) Ltd. | TenPercentOwner | Buy | 1.0M | $15.00 | $15.0M | 1.4M |
| 2025-09-12 | Pontifax Management 4 G.P. (2015) Ltd. | TenPercentOwner | Conversion | 412K | price not stated in the filing | not stated | 412K |
| 2025-09-12 | Deep Track Capital, LP | TenPercentOwner | Buy | 667K | $15.00 | $10.0M | 667K |
| 2025-09-12 | Deep Track Capital, LP | TenPercentOwner | Buy | 2.0M | $15.00 | $30.0M | 2.7M |
| 2025-09-12 | Deep Track Capital, LP | TenPercentOwner | Conversion | 686K | price not stated in the filing | not stated | 686K |
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 LBRX worth $487K at the prices reported; 0 in the last 90 days worth $0. Latest: PRENSKY ZACHARY filed on 2026-06-09 to sell 16,500 shares ($487K) from 2026-06-09.
| Filed | Seller | Shares | Market value | Of outstanding | Sale from | Broker |
|---|---|---|---|---|---|---|
| 2026-06-09 | PRENSKY ZACHARYFormer Officer | 17K | $487K | 0.058% | 2026-06-09 | Stifel Nicolaus & Company Inc |
Large holders (13D and 13G)
One row per reporting person with its latest filing, newest first. JSON24 holders report 5% or more of LBRX in their latest filing, 7 on Schedule 13D (active intent). The largest reported stake is David Kroin at 11.7% of the class (3,352,804 shares), filed 2026-02-10 for an event on 2025-02-06.
| Filed | Form | Holder | Shares | Of class | Event |
|---|---|---|---|---|---|
| 2026-10-13 | 13G/Ano. 1 | JPMORGAN CHASE & CO.parent holding company | 1.4M | 4.3% | 2026-09-30 |
| 2026-08-14 | 13G/Ano. 2 | TCG Crossover Fund II, L.P.partnership | 1.4M | 5.0% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 2 | TCG Crossover GP II, LLCother entity | 1.4M | 5.0% | 2026-06-30 |
| 2026-08-14 | 13G/Ano. 2 | Chen Yuindividual | 1.4M | 5.0% | 2026-06-30 |
| 2026-07-29 | 13G/Ano. 1 | BlackRock, Inc.parent holding company | 1.8M | 6.3% | 2026-06-30 |
| 2026-05-15 | 13G/Ano. 2 | Michael Kramarzparent holding company, individual | 2.0M | 6.8% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Commodore Capital Master LPpartnership | 2.0M | 6.8% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Commodore Capital LPinvestment adviser, partnership | 2.0M | 6.8% | 2026-03-31 |
| 2026-05-15 | 13G/Ano. 2 | Robert Egen Atkinsonparent holding company, individual | 2.0M | 6.8% | 2026-03-31 |
| 2026-05-15 | 13G | Caligan Partners LPinvestment adviser, partnership | 1.4M | 5.0% | 2026-03-31 |
| 2026-05-15 | 13G | JOHNSON DAVID EDWARDparent holding company, individual | 1.4M | 5.0% | 2026-03-31 |
| 2026-02-17 | 13G/Ano. 1 | Peter Kolchinskyparent holding company, individual | 2.2M | 8.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 1 | RA Capital Management, L.P.investment adviser, partnership | 2.2M | 8.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 1 | Rajeev Shahparent holding company, individual | 2.2M | 8.7% | 2025-12-31 |
| 2026-02-17 | 13G/Ano. 1 | RA Capital Healthcare Fund, L.P.partnership | 2.2M | 8.7% | 2025-12-31 |
| 2026-02-10 | 13D/Ano. 1 | David Kroinindividual | 3.4M | 11.7% | 2025-02-06 |
| 2026-02-10 | 13D/Ano. 1 | Deep Track Capital, LPinvestment adviser | 3.4M | 11.7% | 2025-02-06 |
| 2026-02-10 | 13D/Ano. 1 | Deep Track Biotechnology Master Fund, Ltd.other entity | 2.7M | 9.4% | 2025-02-06 |
| 2026-02-10 | 13D/Ano. 1 | Deep Track Special Opportunities Fund, LPpartnership | 667K | 2.3% | 2025-02-06 |
| 2026-01-21 | 13G/Ano. 1 | BlackRock Portfolio Management LLCparent holding company | 961K | 3.8% | 2025-12-31 |
| 2025-12-31 | 13G | Trails Edge Capital Partners, LPinvestment adviser, partnership | 1.3M | 5.0% | 2025-12-24 |
| 2025-12-31 | 13G | Trails Edge Biotechnology Master Fund, LPpartnership | 1.3M | 5.0% | 2025-12-24 |
| 2025-12-31 | 13G | Ortav Yehudaiindividual | 1.3M | 5.0% | 2025-12-24 |
| 2025-09-25 | 13D | Pontifax Management 4 G.P. (2015) Ltd.corporation | 1.4M | 6.3% | 2025-09-12 |
| 2025-09-25 | 13D | Pontifax VI G.P. L.P.partnership | 1.4M | 6.3% | 2025-09-12 |
| 2025-09-25 | 13D | Ran Nussbaumindividual | 1.4M | 6.3% | 2025-09-12 |
| 2025-09-25 | 13D | Tomer Karivindividual | 1.4M | 6.3% | 2025-09-12 |
13F holders
Tracked managers holding LBRX at their latest 13F. JSON4 of the 30 tracked managers held LBRX at their latest 13F, $17.4M in total at quarter-end prices. Millennium Management is the largest at $8.4M (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 3 added shares and 1 cut.
| Fund | Quarter | Shares | Value | Of portfolio | Change in shares |
|---|---|---|---|---|---|
| Millennium Management | 2026-06-30 | 259K | $8.4M | 0.00% | +122K |
| Citadel Advisors | 2026-06-30 | 216K | $7.0M | 0.00% | -201K |
| Two Sigma Investments | 2026-06-30 | 49K | $1.6M | 0.00% | +36K |
| D. E. Shaw & Co. | 2026-06-30 | 14K | $439K | 0.00% | new |
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
LB Pharmaceuticals 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 LB Pharmaceuticals (LBRX), SEC CIK 1691082, listed on Nasdaq. 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 2026-09-18.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 2026-06-09.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 2026-05-12.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 2025-09-12.JSON and CSV
- Company record
- EDGAR filing index for CIK 1691082Ticker, 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 LBRX is sold short?
What is LBRX's daily short volume?
Does LBRX have fails to deliver?
Are LBRX insiders buying or selling?
Have LBRX insiders filed to sell?
Who owns 5% or more of LBRX?
Which tracked 13F managers own LBRX?
Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.