Pulmatrix (PULM)

Pulmatrix on one page: short interest, daily short volume, fails to deliver, large holders, 13F holders and earnings dates. Listed on Nasdaq.

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49K

Short interest

settlement 2026-09-30

1.0

Days to cover

-0.3 days vs prior

34.3%

Short share of volume

2026-10-23

276

Fails to deliver

settlement 2026-08-05

Thu 25 Feb

Next earnings

estimated date

As of 2026-10-23.

Short interest

FINRA, twice a month. The newest 48 settlements in the table, 48 in the chart. JSON

As of 30 September 2026, short interest in PULM is 49,017 shares, up 28,819 shares over the last month. Over the last 48 readings it ranged from 2,505 shares (13 March 2026) to 411,614 shares (15 November 2024). At the reported average volume of 48K shares a day that is 1.0 days to cover.

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Settlement	Shares short	Change	Avg daily volume	Days to cover
2026-09-30	49,017	-11.5%	48,465	1.01
2026-09-15	55,391	+174.2%	43,645	1.27
2026-08-31	20,198	+384.3%	12,801	1.58
2026-08-14	4,171	-75.2%	8,523	1.00
2026-07-31	16,792	-38.9%	12,983	1.29
2026-07-15	27,481	-69.9%	29,455	1.00
2026-06-30	91,267	+816.4%	194,642	1.00
2026-06-15	9,959	-59.9%	31,504	1.00
2026-05-29	24,832	-26.8%	17,947	1.38
2026-05-15	33,902	-16.1%	15,826	2.14
2026-04-30	40,413	+106.2%	43,030	1.00
2026-04-15	19,602	+143.4%	26,450	1.00
2026-03-31	8,053	+221.5%	91,686	1.00
2026-03-13	2,505	-9.9%	82,235	1.00
2026-02-27	2,779	-35.3%	18,863	1.00
2026-02-13	4,293	+2.3%	7,925	1.00
2026-01-30	4,195	-40.4%	10,501	1.00
2026-01-15	7,035	-38.1%	19,600	1.00
2025-12-31	11,368	+164.4%	49,488	1.00
2025-12-15	4,299	-25.1%	13,084	1.00
2025-11-28	5,742	+4.3%	6,790	1.00
2025-11-14	5,504	+6.7%	3,971	1.39
2025-10-31	5,158	-12.8%	11,122	1.00
2025-10-15	5,917	-53.3%	21,066	1.00
2025-09-30	12,682	+251.3%	16,200	1.00
2025-09-15	3,610	-50.5%	5,804	1.00
2025-08-29	7,294	-25.8%	12,240	1.00
2025-08-15	9,830	-42.5%	10,895	1.00
2025-07-31	17,097	-32.6%	8,882	1.92
2025-07-15	25,383	+51.5%	12,760	1.99
2025-06-30	16,754	-45.5%	102,617	1.00
2025-06-13	30,712	+40.1%	22,112	1.39
2025-05-30	21,919	+20.8%	30,508	1.00
2025-05-15	18,153	-23.8%	10,243	1.77
2025-04-30	23,827	-5.3%	8,202	2.91
2025-04-15	25,173	-31.8%	21,343	1.18
2025-03-31	36,921	-2.5%	19,400	1.90
2025-03-14	37,866	+9.4%	25,468	1.49
2025-02-28	34,619	-10.4%	63,337	1.00
2025-02-14	38,644	-26.9%	14,176	2.73
2025-01-31	52,865	+10.9%	28,769	1.84
2025-01-15	47,656	+20.7%	52,259	1.00
2024-12-31	39,484	-47.3%	49,803	1.00
2024-12-13	74,908	+27.8%	130,683	1.00
2024-11-29	58,595	-85.8%	384,035	1.00
2024-11-15	411,614	+5740.1%	2,171,613	1.00
2024-10-31	7,048	+8.1%	12,677	1.00
2024-10-15	6,518	+28.7%	7,041	1.00

Daily short volume

FINRA Reg SHO, the last 30 sessions. JSON

As of 23 October 2026, the short share of PULM volume is 34.3%, down 16.9 points over the last five sessions. Over the last 30 readings it ranged from 1.0% (16 September 2026) to 90.9% (14 September 2026). The latest reading is in line with the 30-session average of 34.6%, on 6K shares reported.

Date	Short volume	Total volume	Short share	Exempt
2026-10-23	2K	6K	34.3%	1,100
2026-10-22	5K	11K	47.9%	250
2026-10-21	22K	49K	45.8%	0
2026-10-20	630	5K	11.8%	0
2026-10-19	9K	15K	60.6%	0
2026-10-16	2K	4K	51.2%	0
2026-10-15	1K	12K	9.0%	0
2026-10-14	883	2K	44.8%	0
2026-10-13	8K	15K	51.9%	0
2026-10-12	1K	3K	39.9%	0
2026-10-09	1K	2K	50.9%	0
2026-10-08	279	9K	3.2%	0
2026-10-07	2K	7K	28.1%	0
2026-10-06	864	15K	5.9%	0
2026-10-05	234	16K	1.5%	0
2026-10-02	705	4K	17.4%	0
2026-10-01	808	5K	14.9%	0
2026-09-30	3K	4K	57.7%	0
2026-09-29	484	4K	11.3%	0
2026-09-28	9K	33K	28.7%	411
2026-09-25	2K	4K	52.6%	0
2026-09-24	3K	8K	38.7%	0
2026-09-23	6K	15K	38.4%	0
2026-09-22	20K	60K	32.5%	0
2026-09-21	83K	150K	55.3%	14
2026-09-18	3K	16K	16.6%	0
2026-09-17	7K	10K	71.2%	0
2026-09-16	141	15K	1.0%	0
2026-09-15	796	3K	25.3%	0
2026-09-14	4K	5K	90.9%	0

Fails to deliver

SEC, the last 30 settlement dates with a fail. JSON

As of 5 August 2026, the fails-to-deliver balance in PULM is 276 shares, up 258 shares over the last settlement date. Over the last 30 readings it ranged from 1 share (24 April 2026) to 7,537 shares (26 June 2026). The latest reading sits at the bottom of that range.

Settlement	Shares failed	Price	Value
2026-08-05	276	$1.66	$458
2026-08-03	18	$1.72	$31
2026-07-09	844	$1.88	$2K
2026-07-01	87	$1.70	$148
2026-06-30	1,576	$1.63	$3K
2026-06-29	51	$1.64	$84
2026-06-26	7,537	$1.67	$13K
2026-06-23	3,165	$1.54	$5K
2026-06-17	3,144	$1.49	$5K
2026-06-15	1,656	$1.40	$2K
2026-06-12	8	$1.38	$11
2026-06-04	1	$1.29	$1
2026-05-08	271	$1.30	$352
2026-04-24	1	$1.40	$1
2026-04-08	542	$1.26	$683
2026-03-31	3,117	$1.23	$4K
2026-03-30	6,307	$1.36	$9K
2026-03-24	106	$2.26	$240
2026-03-20	1,244	$2.15	$3K
2026-03-12	101	$2.21	$223
2026-03-11	100	$2.23	$223
2026-03-09	100	$2.02	$202
2026-03-06	200	$2.14	$428
2026-03-05	200	$2.16	$432
2026-03-04	100	$2.05	$205
2026-03-03	100	$1.89	$189
2026-03-02	100	$2.99	$299
2026-02-27	100	$2.91	$291
2026-02-24	116	$3.11	$361
2026-02-23	100	$2.81	$281

Large holders (13D and 13G)

One row per reporting person with its latest filing, newest first. JSON

3 holders report 5% or more of PULM in their latest filing, all on Schedule 13D (active intent). The largest reported stake is Rapha Capital Management, LLC at 10.0% of the class (405,358 shares), filed 2026-04-22 for an event on 2026-04-16.

Filed	Form	Holder	Shares	Of class	Event
2026-04-22	13D	Rapha Capital Management, LLCother entity	405K	10.0%	2026-04-16
2026-04-22	13D	Slawin Kevin M.individual	405K	10.0%	2026-04-16
2026-04-22	13D	RCM Eos PIPE HOLDINGS, LLCother entity	405K	10.0%	2026-04-16

13F holders

Tracked managers holding PULM at their latest 13F. JSON

1 of the 30 tracked managers held PULM at their latest 13F, $209K in total at quarter-end prices. Renaissance Technologies is the largest at $209K (0.0% of its portfolio) as of 2026-06-30. Over the prior quarter 1 added shares and 0 cut.

Fund	Quarter	Shares	Value	Of portfolio	Change in shares
Renaissance Technologies	2026-06-30	123K	$209K	0.00%	+14K

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

Pulmatrix 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 Pulmatrix (PULM), SEC CIK 1574235, 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 2026-09-30.JSON and CSV
Daily short volume: FINRA Reg SHO daily filesSource: FINRA.Every trading day, the morning after FINRA posts it. Latest 2026-10-23.JSON and CSV
Fails to deliver: SEC fails-to-deliver dataSource: SEC.Twice a month, a few weeks after the half month ends. Latest 2026-08-05.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 2026-04-22.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 2026-08-13.JSON and CSV
Company record: EDGAR filing index for CIK 1574235Ticker, 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.

Datasets

Frequently Asked Questions

How much of PULM is sold short?

49,017 shares were held short at the 2026-09-30 settlement, 1.0 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 PULM's daily short volume?

On 2026-10-23, 1,930 of the 5,626 PULM shares reported to FINRA were sold short, 34.3% of the day's reported volume. Short volume is a flow for one day, not a position.

Does PULM have fails to deliver?

The SEC's latest file shows 276 PULM shares failed to deliver at settlement 2026-08-05. Fails are reported per settlement date and published twice a month with a lag.

Are PULM insiders buying or selling?

No Form 4 filings for PULM are on record.

Who owns 5% or more of PULM?

Which tracked 13F managers own PULM?

1 of the 30 tracked 13F managers held PULM shares at their latest filing, $209K in all. The largest: Renaissance Technologies (123K shares, $209K).

Data on this page is provided for informational purposes only and is not financial advice. See our editorial policy.

Pulmatrix (PULM)

Short interest

Daily short volume

Fails to deliver

Large holders (13D and 13G)

13F holders

Pulmatrix in the regulatory record

Source and updates

How to read it

Other company pages

Datasets

Frequently Asked Questions