AC Immune SA Insider Ownership | ACIU

Insider Holdings by Owner

8.00Mn Shares

Insider Ownership Statistics

as of 30 Sep, 2026

Insider Ownership

4.14%

■0% pp QoQ

Shares Held by Insiders

4.17Mn

filed for Sep 2026

■0.00% QoQ

Shares Outstanding

100.75Mn

100,751,705 shares

Direct Holdings

4.17Mn

Indirect: 0

Net Shares Traded (QoQ)

0

no net change in Sep 2026

Insiders Holding Shares

6

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 5, 2026

In the last 12 months, insiders at AC Immune made open-market purchases of $31,425 (10K shares) and open-market sales of $59,360 (20K shares).

Among AC Immune insiders, Andrea Pfeifer (Chief Executive Officer) led open-market buying over the past 12 months with $31,425 of purchases (10K shares); the latest was on April 15, 2026.
Conversely, Andrea Pfeifer (Chief Executive Officer) was ACIU's largest open-market seller in the past 12 months, with $59,360 of sales (20K shares); the latest was on May 15, 2026.
Apart from open-market trades, ACIU insiders received 67.45K shares in stock awards in the past 12 months.
Business Quant data shows AC Immune insiders holding 4.17Mn shares in total in their latest Form 4 filings, unchanged from 4.17Mn shares at the end of Q2 2026.
ACIU's insiders hold all 4.17Mn shares directly, in their own names, with no indirect holdings.
Per Business Quant, 6 insiders of ACIU hold shares, counting officers, directors and 10% owners who have filed a Form 4 in the past two years.
AC Immune's top three insider holders by shares held are Andrea Pfeifer (Chief Executive Officer, 3.82Mn shares), Roy Ervin Twyman (Director, 92.56K shares) and Monika Buetler (Director, 71.66K shares).
Andrea Pfeifer holds 91.51% of the combined insider position in AC Immune.
Institutions held 24.29% of AC Immune's outstanding shares in their Q2 2026 13F filings, insiders about 4.14% based on their latest Form 4 filings, and other investors, including the public, the remaining 71.57%.
Over the past 12 months, 6 insiders reported transactions in AC Immune stock in 8 Form 4 filings.
The insider data for ACIU reflects Form 4 filings through June 15, 2026.

Form 4 Holdings

Insiders Holding ACIU

Insiders 6

Shares held 8.00Mn

Of outstanding 7.95%

#	Insider	Position	Direct	Total	Share of Insiders	Last Filed
1	Andrea Pfeifer	Chief Executive Officer	7,650,576	7,650,576	95.6%	18 May, 2026
2	Roy Ervin Twyman	Director	92,556	92,556	1.2%	15 Jun, 2026
3	Monika Buetler	Director	71,656	71,656	0.9%	15 Jun, 2026
4	Martin Zuegel	Interim Ceo	71,408	71,408	0.9%	15 Jun, 2026
5	Carl Howard June	Director	67,556	67,556	0.8%	15 Jun, 2026
6	Renee Aguiar-Lucander	Director	51,136	51,136	0.6%	15 Jun, 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

13 Insider Transactions

Source SEC Form 4

Latest quarter Sep 2026

Date	Insider	Position	Transaction	Shares	Price	Value	Shares Held After	Ownership
11 Jun, 2026	Martin Zuegel	Interim Ceo	Acquired A	33,136	$0.00	$0	71,408	Direct
11 Jun, 2026	Renee Aguiar-Lucander	Director	Acquired A	16,568	$0.00	$0	51,136	Direct
11 Jun, 2026	Monika Buetler	Director	Acquired A	17,751	$0.00	$0	71,656	Direct
11 Jun, 2026	Carl Howard June	Director	Acquired A	16,568	$0.00	$0	67,556	Direct
11 Jun, 2026	Roy Ervin Twyman	Director	Acquired A	16,568	$0.00	$0	92,556	Direct
11 Jun, 2026	Martin Zuegel	Interim Ceo	Acquired A	77,778	$0.00	$0	77,778	Direct
11 Jun, 2026	Renee Aguiar-Lucander	Director	Acquired A	38,889	$0.00	$0	38,889	Direct
11 Jun, 2026	Carl Howard June	Director	Acquired A	38,889	$0.00	$0	38,889	Direct
11 Jun, 2026	Monika Buetler	Director	Acquired A	41,667	$0.00	$0	41,667	Direct
11 Jun, 2026	Roy Ervin Twyman	Director	Acquired A	38,889	$0.00	$0	38,889	Direct
15 May, 2026	Andrea Pfeifer	Chief Executive Officer	Disposed S	10,000	$2.79	$27.94K	3,820,288	Direct
15 Apr, 2026	Andrea Pfeifer	Chief Executive Officer	Disposed P	10,000	$3.14	$31.43K	3,830,288	Direct
15 Apr, 2026	Andrea Pfeifer	Chief Executive Officer	Disposed S	10,000	$3.14	$31.43K	3,830,288	Direct

AC Immune ACIU Insider Ownership