National Storage Mechanism | Additional information

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FORM 8.3

IRISH TAKEOVER PANEL

OPENING POSITION DISCLOSURE/DEALING DISCLOSURE UNDER RULE 8.3 OF THE IRISH TAKEOVER PANEL ACT, 1997, TAKEOVER

RULES, 2022 BY PERSONS WITH INTERESTS IN RELEVANT SECURITIES REPRESENTING 1% OR MORE

1. KEY INFORMATION

(a) Full name of discloser	Citadel Group
(b) Owner or controller of interests and short positions disclosed, if different from 1(a) The naming of nominee or vehicle companies is insufficient. For a trust, the trustee(s), settlor and beneficiaries must be named.	N/A
(c) Name of offeror/offeree in relation to whose relevant securities this form relates Use a separate form for each offeror/offeree	HORIZON THERAPEUTICS PLC
(d) If an exempt fund manager connected with an offeror/offeree, state this and specify identity of offeror/offeree (Note 1)	N/A
(e) Date position held/dealing undertaken For an opening position disclosure, state the latest practicable date prior to the disclosure	4 May 2023
(f) In addition to the company in 1(c) above, is the discloser also making disclosures in respect of any other party to the offer? If it is a cash offer or possible cash offer, state "N/A"	N/A

2. INTERESTS AND SHORT POSITIONS

If there are interests and short positions to disclose in more than one class of relevant securities of the offeror or offeree named in 1(c), copy table 2 for each additional class of relevant security.

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Interests and short positions in the relevant securities of the offeror or offeree to which the disclosure relates following the dealing (if any)

(Note 2)

Class of relevant security (Note 3)	Common Stock ISIN IE00BQPVQZ61
	Interests		Short positions
	Number	%	Number	%
(1) Relevant securities owned and/or controlled	3,550,052	1.55	0	0.00
(2) Cash-settled derivatives	0	0.00	0	0.00
(3) Stock-settled derivatives (including options) and agreements to purchase/ sell	410,000	0.17	360,000	0.15
Total	3,960,052	1.73	360,000	0.15

All interests and all short positions should be disclosed.

Details of options including rights to subscribe for new securities and any open stock-settled derivative positions (including traded options), or agreements to purchase or sell relevant securities, should be given on a Supplemental Form 8.

3. DEALINGS (IF ANY) BY THE PERSON MAKING THE DISCLOSURE (Note 4)

Where there have been dealings in more than one class of relevant securities of the offeror or offeree named in 1(c), copy table 3(a), (b), (c) or (d) (as appropriate) for each additional class of relevant security dealt in.

The currency of all prices and other monetary amounts should be stated.

(a) Purchases and sales

Class of relevant security	Purchase/sale	Number of securities	Price per unit (Note 5)
Common	Buy Transaction	574	110.1674 USD
Common	Buy Transaction	1,000	110.2000 USD
Common	Buy Transaction	18,140	110.2151 USD
Common	Buy Transaction	100	110.2300 USD
Common	Buy Transaction	42,459	110.3062 USD
Common	Buy Transaction	801	110.3502 USD
Common	Buy Transaction	20,000	110.3945 USD
Common	Buy Transaction	100	110.4000 USD
Common	DVP Transaction	3,510	110.2900 USD
Common	RVP Transaction	3,510	110.2900 USD
Common	Sell Transaction	16	110.1850 USD
Common	Sell Transaction	30	110.1897 USD
Common	Sell Transaction	14	110.1900 USD
Common	Sell Transaction	178	110.1912 USD
Common	Sell Transaction	9	110.2000 USD
Common	Sell Transaction	3	110.2083 USD
Common	Sell Transaction	42	110.2302 USD
Common	Sell Transaction	222	110.2316 USD
Common	Sell Transaction	302	110.2317 USD
Common	Sell Transaction	671	110.2320 USD
Common	Sell Transaction	131	110.2325 USD
Common	Sell Transaction	520	110.2332 USD
Common	Sell Transaction	73	110.2351 USD
Common	Sell Transaction	48	110.2358 USD
Common	Sell Transaction	112	110.2361 USD
Common	Sell Transaction	39	110.2362 USD
Common	Sell Transaction	179	110.2363 USD
Common	Sell Transaction	248	110.2364 USD
Common	Sell Transaction	247	110.2365 USD
Common	Sell Transaction	546	110.2367 USD
Common	Sell Transaction	51	110.2371 USD
Common	Sell Transaction	22	110.2373 USD
Common	Sell Transaction	82	110.2374 USD
Common	Sell Transaction	105	110.2377 USD
Common	Sell Transaction	18	110.2417 USD
Common	Sell Transaction	53	110.2436 USD
Common	Sell Transaction	158	110.2441 USD
Common	Sell Transaction	366	110.2442 USD
Common	Sell Transaction	265	110.2442 USD
Common	Sell Transaction	101	110.2442 USD
Common	Sell Transaction	813	110.2444 USD
Common	Sell Transaction	306	110.2453 USD
Common	Sell Transaction	138	110.2456 USD
Common	Sell Transaction	60	110.2457 USD
Common	Sell Transaction	21	110.2462 USD
Common	Sell Transaction	80	110.2475 USD
Common	Sell Transaction	24	110.2506 USD
Common	Sell Transaction	1	110.2600 USD
Common	Sell Transaction	3,508	110.2900 USD
Common	Sell Transaction	13	110.3019 USD
Common	Sell Transaction	104	110.3069 USD
Common	Sell Transaction	197	110.3149 USD
Common	Sell Transaction	124	110.3150 USD
Common	Sell Transaction	89	110.3152 USD
Common	Sell Transaction	66	110.3157 USD
Common	Sell Transaction	39	110.3158 USD
Common	Sell Transaction	14	110.3175 USD
Common	Sell Transaction	836	110.3187 USD
Common	Sell Transaction	361	110.3193 USD
Common	Sell Transaction	1,848	110.3196 USD
Common	Sell Transaction	611	110.3200 USD
Common	Sell Transaction	174	110.3256 USD
Common	Sell Transaction	300	110.3450 USD
Common	Sell Transaction	292	110.3602 USD
Common	Sell Transaction	600	110.4233 USD
Common	Sell Transaction	1	110.4500 USD
Common	Sell Transaction	3	110.5000 USD

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(b) Cash-settled derivative transactions

Class of
relevant
security

Product
description
e.g. CFD

Nature of dealing
e.g. opening/ closing a long/ short position, increasing/ reducing a long/ short position

Number of
reference
securities
(Note 6)

Price
per unit
(Note 5)

(i) Writing, selling, purchasing or varying

Class of
relevant
security

Product
description e.g. call
option

Writing, purchasing, selling, varying
etc.

Number
of
securities
to which
option
relates
(Note 6)

Exercise
price per
unit

Type
e.g.
American,
European
etc.

Expiry
date

Option
money
paid/
received per unit

(ii) Exercise

Class of
relevant
security

Product
description
e.g. call
option

Exercising/
exercised
against

Number of
securities

Exercise
price per
unit
(Note 5)

(d) Other dealings (including transactions in respect of new securities) (Note 3)

Class of relevant security	Nature of dealing e.g. subscription, conversion, exercise	Details	Price per unit (if applicable) (Note 5)

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4. OTHER INFORMATION

(a) Indemnity and other dealing arrangements

Details of any indemnity or option arrangement, or any agreement or understanding, formal or informal, relating to relevant securities which may be an inducement to deal or refrain from dealing entered into by the person making the disclosure and any party to the offer or any person acting in concert with a party to the offer.

Irrevocable commitments and letters of intent should not be included. If there are no such agreements, arrangements or understandings, state "none"

None

(b) Agreements, arrangements or understandings relating to options or derivatives

Full details of any agreement, arrangement or understanding between the person disclosing and any other person relating to the voting rights of any relevant securities under any option referred to on this form or relating to the voting rights or future acquisition or disposal of any relevant securities to which any derivative referred to on this form is referenced. If none, this should be stated.

None

Is a Supplemental Form 8 attached?

YES

Date of disclosure	5 May 2023
Contact name	Paula Sharp
Telephone number	020 7645 9700

Public disclosures under Rule 8.3 of the Rules must be made to a Regulatory Information Service.

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SUPPLEMENTAL FORM 8

IRISH TAKEOVER PANEL

DISCLOSURE UNDER RULE 8.1, RULE 8.3, RULE 38.5(b) AND
RULE 38.6 OF THE IRISH TAKEOVER PANEL ACT, 1997,
TAKEOVER RULES, 2022

DETAILS OF OPEN STOCK-SETTLED DERIVATIVE (INCLUDING
OPTION) POSITIONS, AGREEMENTS TO PURCHASE OR SELL AND
RIGHTS TO SUBSCRIBE FOR NEW SECURITIES

1. KEY INFORMATION

Full name of person making disclosure:	Citadel Group
Name of offeror/offeree in relation to whose relevant securities the disclosure relates:	HORIZON THERAPEUTICS PLC

2. STOCK-SETTLED DERIVATIVES (INCLUDING OPTIONS)

Class of relevant security	Product description e.g. call option	Written or purchased	Number of securities to which option or derivative relates	Exercise price per unit	Type e.g. American, European etc.	Expiry date
Common	Put Option	Sold	50,000	100 USD	American	18/08/2023
Common	Call Option	Purchased	50,000	115 USD	American	18/08/2023
Common	Put Option	Sold	30,000	100 USD	American	19/05/2023
Common	Put Option	Sold	280,000	90 USD	American	21/07/2023
Common	Put Option	Purchased	- 50,000	80 USD	American	18/08/2023
Common	Put Option	Purchased	- 30,000	85 USD	American	19/05/2023
Common	Put Option	Purchased	- 280,000	105 USD	American	21/07/2023

3. AGREEMENTS TO PURCHASE OR SELL

Full details should be given so that the nature of the interest or position can be fully understood:

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4. RIGHTS TO SUBSCRIBE FOR NEW SECURITIES (INCLUDING DIRECTORS' AND OTHER EMPLOYEE OPTIONS)

Class of relevant security in relation to which subscription right exists:
Details, including nature of the rights concerned and relevant percentages:

It is not necessary to provide details on a Supplemental Form with regard to cash-settled derivatives.

The currency of all prices and other monetary amounts should be stated.

For full details of disclosure requirements, see Rule 8 of the Rules. If in doubt, consult the Panel.

References in these notes to "the Rules" are to the Irish Takeover Panel Act, 1997, Takeover Rules, 2022.