Aeluma ALMU Insider Ownership

NASDAQ ALMU

$6.91 -0.26 (-3.63%)

At close: Oct 23, 2026 · 4:00 PM EDT

Insider Holdings by Owner

6.08Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

18.22%

▼-0.099% pp QoQ

Shares Held by Insiders

3.51Mn

filed for Sep 2026

▼-0.54% QoQ

Shares Outstanding

19.27Mn

19,265,671 shares

Direct Holdings

2.28Mn

Indirect: 1.23Mn

Net Shares Traded (QoQ)

-18.98K

net selling in Sep 2026

Insiders Holding Shares

with Form 4 holdings on file

Shares Owned by Insiders

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Insiders

Bought Sold

Latest quarter —

Net over range —

Buying quarters —

Insider Ownership Summary

Updated Oct 22, 2026

Across the past 12 months, open-market trades by Aeluma insiders were all sales, totaling $14.84 million (934.5K shares).

Counted by insider, open-market selling of ALMU stock in the past 12 months came from 3 insiders, with no insider buying.
Mark N. Tompkins led open-market sales of Aeluma stock over the past 12 months with $8.76 million (529.5K shares), most recently on February 4, 2026.
The newest open-market trade among Aeluma insiders came on October 12, 2026, when Jonathan Klamkin (Chief Executive Officer) made a sale of 100K shares for $1.05 million.
Beyond open-market trades, insiders at Aeluma received 64.37K shares in stock awards, acquired 25K shares through option exercises and conversions, gave up 11.69K shares to cover taxes or exercise prices and gave away 60K shares as gifts in the last 12 months.
Business Quant data puts insider holdings in ALMU at 3.41Mn shares across insiders' latest Form 4 filings, down 3.37% from 3.53Mn shares at the end of Q2 2026 and down 27.63% from 4.71Mn shares at the end of Q3 2025.
Aeluma insiders hold 2.28Mn shares directly (66.96% of their total) and 1.13Mn shares (33.04%) indirectly, through entities such as trusts and partnerships.
The insider holdings in Aeluma belong to 5 insiders who have reported on Form 4 within the past two years.
Aeluma's three biggest insider holders are Mark N. Tompkins (1.79Mn shares), Jonathan Klamkin (Chief Executive Officer, 1.17Mn shares) and Steven Denbaars (Director, 345.21K shares), based on their latest Form 4 filings.
Mark N. Tompkins holds 52.49% of the combined insider position in Aeluma.
Institutions held 28.18% of Aeluma's outstanding shares in their Q2 2026 13F filings, insiders about 17.71% based on their latest Form 4 filings, and other investors, including the public, the remaining 54.11%.
A total of 21 Form 4 filings with transactions in Aeluma stock were made over the past 12 months, by 5 insiders.
This summary of Aeluma insider activity covers Form 4 filings through October 14, 2026.

Form 4 Holdings

Insiders Holding ALMU

Insiders 5

Shares held 6.08Mn

Of outstanding 31.58%

#	Insider	Position	Direct	Indirect	Total	Share of Insiders	Last Filed
1	Mark N. Tompkins	Other	4,506,321	0	4,506,321	74.1%	05 Feb, 2026
2	Jonathan Klamkin	Chief Executive Officer	0	1,126,995	1,126,995	18.5%	14 Oct, 2026
3	Steven Denbaars	Director	345,209	0	345,209	5.7%	28 Aug, 2026
4	Christopher P. Stewart	Chief Financial Officer	67,781	0	67,781	1.1%	01 Oct, 2026
5	Michael Byron	Director	38,343	0	38,343	0.6%	23 Sep, 2026

Each row is that insider’s most recently reported position, from Form 4 filings over the last 60 months — which is why this total does not tie to the quarterly series above, where a quarter counts only the insiders who filed in it. Shares held through a fund or institutional portfolio are counted on the institutional ownership page instead.

Form 4 Filings

123 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
12 Oct, 2026	Jonathan Klamkin	Chief Executive Officer	Disposed S	100,000	$10.53	$1.05Mn	1,126,995	Indirect
30 Sep, 2026	Christopher P. Stewart	Chief Financial Officer	Disposed F	5,697	$12.36	$70.41K	67,781	Direct
21 Sep, 2026	Christopher P. Stewart	Chief Financial Officer	Acquired A	15,886	$0.00	$0	15,886	Direct
21 Sep, 2026	Jonathan Klamkin	Chief Executive Officer	Disposed S	100,000	$13.35	$1.34Mn	1,226,995	Indirect
21 Sep, 2026	Michael Byron	Director	Acquired M	25,000	$5.93	$148.25K	38,343	Direct
21 Sep, 2026	Michael Byron	Director	Disposed M	25,000	$0.00	$0	20,833	Direct
21 Sep, 2026	Christopher P. Stewart	Chief Financial Officer	Acquired A	4,042	$0.00	$0	19,928	Direct
21 Sep, 2026	Jonathan Klamkin	Chief Executive Officer	Acquired A	31,771	$0.00	$0	34,174	Direct
21 Sep, 2026	Christopher P. Stewart	Chief Financial Officer	Disposed F	1,450	$13.61	$19.73K	18,478	Direct
21 Sep, 2026	Jonathan Klamkin	Chief Executive Officer	Acquired A	12,675	$0.00	$0	46,849	Direct
21 Sep, 2026	Christopher P. Stewart	Chief Financial Officer	Acquired A	37,568	$0.00	$0	37,568	Direct
21 Sep, 2026	Jonathan Klamkin	Chief Executive Officer	Disposed F	4,547	$13.61	$61.88K	42,302	Direct
21 Sep, 2026	Jonathan Klamkin	Chief Executive Officer	Acquired A	75,135	$0.00	$0	75,135	Direct
26 Aug, 2026	Steven Denbaars	Director	Disposed S	12,500	$13.84	$173.04K	357,709	Direct
26 Aug, 2026	Steven Denbaars	Director	Disposed S	12,500	$13.84	$173.04K	357,709	Direct
27 Aug, 2026	Steven Denbaars	Director	Disposed S	12,500	$13.82	$172.70K	345,209	Direct
27 Aug, 2026	Steven Denbaars	Director	Disposed S	12,500	$13.82	$172.70K	345,209	Direct
03 Aug, 2026	Jonathan Klamkin	Chief Executive Officer	Disposed G	20,000	$0.00	$0	1,326,995	Indirect
03 Aug, 2026	Jonathan Klamkin	Chief Executive Officer	Acquired G	20,000	$0.00	$0	22,403	Direct
03 Aug, 2026	Jonathan Klamkin	Chief Executive Officer	Disposed S	4,190	$16.29	$68.26K	18,213	Direct

Showing 1 to 20 of 123 transactions