AC Immune (ACIU) CEO adds 10,000 shares in open-market buy

Rhea-AI Filing Summary

AC Immune SA Chief Executive Officer Andrea Pfeifer reported an open-market purchase of 10,000 common shares on April 15, 2026 at a weighted average price of $3.1425 per share, with individual trades ranging from $3.05 to $3.19.

Following this transaction, she directly owns 3,830,288 shares, which include 1,921,005 common shares underlying outstanding restricted share units. In addition, 14,000 shares are reported as indirectly owned through her spouse.

Insider Trade Summary 10b5-1

Net Buyer: 10,000 shares ($31,425)

Net Buy 2 txns

Insider Pfeifer Andrea

Role Chief Executive Officer

Bought 10,000 shs ($31K)

Type	Security	Shares	Price	Value
Purchase	Share	10,000	$3.1425	$31K
holding	Share	--	--	--

Holdings After Transaction: Share — 3,830,288 shares (Direct); Share — 14,000 shares (Indirect, By spouse)

Footnotes (1)

1. Includes 1,921,005 common shares underlying outstanding restricted share units. The price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.05 to $3.19, inclusive.

Key Figures

Shares purchased: 10,000 shares Weighted average purchase price: $3.1425 per share Direct holdings after transaction: 3,830,288 shares +3 more

6 metrics

Shares purchased 10,000 shares Open-market purchase on April 15, 2026

Weighted average purchase price $3.1425 per share Open-market buy on April 15, 2026

Direct holdings after transaction 3,830,288 shares Common shares directly owned after April 15, 2026 trade

Shares underlying RSUs 1,921,005 shares Common shares underlying outstanding restricted share units included in direct holdings

Indirect spouse holdings 14,000 shares Common shares held indirectly by spouse

Price range of purchases $3.05–$3.19 per share Individual trades on April 15, 2026

Key Terms

open-market purchase, restricted share units, weighted average price, indirectly owned

4 terms

open-market purchase financial

"reported an open-market purchase of 10,000 common shares"

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

restricted share units financial

"includes 1,921,005 common shares underlying outstanding restricted share units"

Restricted share units (RSUs) are a promise from a company to give an employee or service provider actual shares or cash equal to the shares after certain conditions are met, typically staying with the company for a set time or hitting performance targets. Think of them like a time-locked gift card that becomes usable only after you’ve earned it. For investors, RSUs matter because they align employee incentives with company performance and can increase the number of shares outstanding over time, diluting existing ownership and affecting earnings per share.

weighted average price financial

"at a weighted average price of $3.1425 per share"

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

indirectly owned financial

"14,000 shares are reported as indirectly owned through her spouse"

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Pfeifer Andrea

(Last) (First) (Middle)

C/O AC IMMUNE SA

EPFL INNOVATION PARK BUILDING B

(Street)

LAUSANNE 1015

(City) (State) (Zip)

SWITZERLAND

(Country)

2. Issuer Name and Ticker or Trading Symbol
AC Immune SA [ ACIU ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
04/15/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Share	04/15/2026		P		10,000	D	$3.1425(2)	3,830,288(1)	D
Share								14,000	I	By spouse

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Includes 1,921,005 common shares underlying outstanding restricted share units.

2. The price is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.05 to $3.19, inclusive.

	Matthias Maurer	04/16/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did AC Immune (ACIU) report for CEO Andrea Pfeifer?

AC Immune reported that CEO Andrea Pfeifer bought 10,000 common shares in an open-market purchase on April 15, 2026. The weighted average purchase price was $3.1425 per share, reflecting multiple trades within a narrow price range.

At what prices did AC Immune’s CEO buy ACIU shares in this Form 4?

Andrea Pfeifer purchased 10,000 AC Immune shares at a weighted average price of $3.1425 per share. According to the filing, individual trades occurred at prices ranging from $3.05 to $3.19, all on April 15, 2026.

How many AC Immune (ACIU) shares does the CEO hold after this transaction?

After the reported trade, CEO Andrea Pfeifer directly holds 3,830,288 AC Immune shares. This total includes 1,921,005 common shares underlying outstanding restricted share units, giving a clearer view of her combined equity and equity-based compensation position.

Does the AC Immune CEO have any indirect ownership in ACIU shares?

Yes. In addition to her direct holdings, the filing shows 14,000 AC Immune shares held indirectly by her spouse. These spouse-held shares are reported separately from her direct position but are still disclosed within the overall ownership picture.

What does the Form 4 reveal about AC Immune CEO’s restricted share units?

The Form 4 notes that Andrea Pfeifer’s direct holdings of 3,830,288 shares include 1,921,005 common shares underlying outstanding restricted share units. This highlights a significant component of her compensation tied to AC Immune’s equity performance.