Form 8.3

CHICAGO--(BUSINESS WIRE)-- 

FORM 8.3

PUBLIC OPENING POSITION DISCLOSURE/DEALING DISCLOSURE BY

A PERSON WITH INTERESTS IN RELEVANT SECURITIES REPRESENTING 1% OR MORE

Rule 8.3 of the Takeover Code (the “Code”)

1. KEY INFORMATION

(a) Full name of discloser:	Driehaus Capital Management LLC
(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	Senior plc
(d) If an exempt fund manager connected with an offeror/offeree, state this and specify identity of offeror/offeree:	N/A
(e) Date position held/dealing undertaken: For an opening position disclosure, state the latest practicable date prior to the disclosure	18 June 2026
(f) In addition to the company in 1(c) above, is the discloser making disclosures in respect of any other party to the offer? If it is a cash offer or possible cash offer, state “N/A”	NO

2. POSITIONS OF THE PERSON MAKING THE DISCLOSURE

If there are positions or rights to subscribe to disclose in more than one class of relevant securities of the offeror or offeree named in 1(c), copy table 2(a) or (b) (as appropriate) for each additional class of relevant security.

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

Class of relevant security:	10p ordinary
	Interests		Short positions
	Number	%	Number	%
(1) Relevant securities owned and/or controlled:	14,049,066	3.34
(2) Cash-settled derivatives:
(3) Stock-settled derivatives (including options) and agreements to purchase/sell:
TOTAL:	14,049,066	3.34

All interests and all short positions should be disclosed.

Details of 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 (Open Positions).

(b) 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:

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

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
10p Ordinary	Sale	248.61	2.8775
10p Ordinary	Sale	673.19	2.8775
10p Ordinary	Sale	1380.49	2.8775
10p Ordinary	Sale	444.19	2.8775
10p Ordinary	Sale	566.55	2.8775
10p Ordinary	Sale	8116.58	2.8775
10p Ordinary	Sale	2070.70	2.8775
10p Ordinary	Sale	129.68	2.8775
10p Ordinary	Sale	352.81	2.8775
10p Ordinary	Sale	315.70	2.8775
10p Ordinary	Sale	444.66	2.8775
10p Ordinary	Sale	255.73	2.8775
10p Ordinary	Sale	3812.70	2.8775
10p Ordinary	Sale	1084.63	2.8775
10p Ordinary	Sale	406.35	2.8775
10p Ordinary	Sale	564.28	2.8775
10p Ordinary	Sale	128.19	2.8775
10p Ordinary	Sale	1443.73	2.8775
10p Ordinary	Sale	472.21	2.8775
10p Ordinary	Sale	2339.48	2.8775
10p Ordinary	Sale	3283.49	2.8775
10p Ordinary	Sale	111.38	2.8775
10p Ordinary	Sale	279.12	2.8775
10p Ordinary	Sale	2311.48	2.8775
10p Ordinary	Sale	1044.16	2.8775
10p Ordinary	Sale	1256.40	2.8775
10p Ordinary	Sale	365.24	2.8775
10p Ordinary	Sale	743.72	2.8775
10p Ordinary	Sale	1977.44	2.8775
10p Ordinary	Sale	2145.32	2.8775
10p Ordinary	Sale	404.04	2.8775
10p Ordinary	Sale	74.82	2.8775
10p Ordinary	Sale	1393.52	2.8775
10p Ordinary	Sale	1014.15	2.8775
10p Ordinary	Sale	1785.77	2.8775
10p Ordinary	Sale	1100.69	2.8775
10p Ordinary	Sale	584.99	2.8775
10p Ordinary	Sale	1728.72	2.8775
10p Ordinary	Sale	12.61	2.8775
10p Ordinary	Sale	545.72	2.8775
10p Ordinary	Sale	255.22	2.8775
10p Ordinary	Sale	5736.70	2.8775
10p Ordinary	Sale	1482.09	2.8775
10p Ordinary	Sale	511.45	2.8775
10p Ordinary	Sale	814.39	2.8775
10p Ordinary	Sale	747.84	2.8775
10p Ordinary	Sale	426.16	2.8775
10p Ordinary	Sale	1423.23	2.8775
10p Ordinary	Sale	1008.41	2.8775
10p Ordinary	Sale	1737.06	2.8775
10p Ordinary	Sale	1072.51	2.8775
10p Ordinary	Sale	699.72	2.8775
10p Ordinary	Sale	392.05	2.8775
10p Ordinary	Sale	258.95	2.8775
10p Ordinary	Sale	868.62	2.8775
10p Ordinary	Sale	2352.05	2.8775
10p Ordinary	Sale	4823.28	2.8775
10p Ordinary	Sale	1551.96	2.8775
10p Ordinary	Sale	1979.47	2.8775
10p Ordinary	Sale	28358.36	2.8775
10p Ordinary	Sale	7234.77	2.8775
10p Ordinary	Sale	453.07	2.8775
10p Ordinary	Sale	1232.66	2.8775
10p Ordinary	Sale	1103.00	2.8775
10p Ordinary	Sale	1553.59	2.8775
10p Ordinary	Sale	893.48	2.8775
10p Ordinary	Sale	13321.13	2.8775
10p Ordinary	Sale	3789.58	2.8775
10p Ordinary	Sale	1419.73	2.8775
10p Ordinary	Sale	1971.54	2.8775
10p Ordinary	Sale	447.87	2.8775
10p Ordinary	Sale	5044.22	2.8775
10p Ordinary	Sale	1649.84	2.8775
10p Ordinary	Sale	8173.85	2.8775
10p Ordinary	Sale	11472.13	2.8775
10p Ordinary	Sale	389.13	2.8775
10p Ordinary	Sale	975.21	2.8775
10p Ordinary	Sale	8076.04	2.8775
10p Ordinary	Sale	3648.19	2.8775
10p Ordinary	Sale	4389.71	2.8775
10p Ordinary	Sale	1276.09	2.8775
10p Ordinary	Sale	2598.48	2.8775
10p Ordinary	Sale	6908.95	2.8775
10p Ordinary	Sale	7495.49	2.8775
10p Ordinary	Sale	1411.65	2.8775
10p Ordinary	Sale	261.42	2.8775
10p Ordinary	Sale	4868.81	2.8775
10p Ordinary	Sale	3543.31	2.8775
10p Ordinary	Sale	6239.28	2.8775
10p Ordinary	Sale	3845.67	2.8775
10p Ordinary	Sale	2043.87	2.8775
10p Ordinary	Sale	6039.94	2.8775
10p Ordinary	Sale	44.05	2.8775
10p Ordinary	Sale	1906.67	2.8775
10p Ordinary	Sale	891.69	2.8775
10p Ordinary	Sale	20043.35	2.8775
10p Ordinary	Sale	5178.23	2.8775
10p Ordinary	Sale	1786.96	2.8775
10p Ordinary	Sale	2845.37	2.8775
10p Ordinary	Sale	2612.85	2.8775
10p Ordinary	Sale	1488.95	2.8775
10p Ordinary	Sale	4972.60	2.8775
10p Ordinary	Sale	3523.27	2.8775
10p Ordinary	Sale	6069.07	2.8775
10p Ordinary	Sale	3747.24	2.8775
10p Ordinary	Sale	2444.74	2.8775
10p Ordinary	Sale	1369.78	2.8775
10p Ordinary	Sale	904.74	2.8775
10p Ordinary	Sale	3914.00	2.8775
10p Ordinary	Sale	33298.00	2.8775
10p Ordinary	Sale	73012.00	2.8775
10p Ordinary	Sale	10487.00	2.8775
10p Ordinary	Sale	37214.00	2.8775
10p Ordinary	Sale	9298.00	2.8775
10p Ordinary	Sale	18058.00	2.8775
10p Ordinary	Sale	10995.00	2.8775
10p Ordinary	Sale	35812.00	2.8775
10p Ordinary	Sale	3426.00	2.8775
10p Ordinary	Sale	3297.00	2.8775
10p Ordinary	Sale	2968.00	2.8775
10p Ordinary	Sale	6593.00	2.8775

(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

Price per unit

(c) Stock-settled derivative transactions (including options)

(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

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

(d) Other dealings (including subscribing for new securities)

Class of relevant security

Nature of dealing e.g. subscription, conversion

Details

Price per unit (if applicable)

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

Details of any agreement, arrangement or understanding, formal or informal, between the person making the disclosure and any other person relating to: (i) the voting rights of any relevant securities under any option; or (ii) the voting rights or future acquisition or disposal of any relevant securities to which any derivative is referenced: If there are no such agreements, arrangements or understandings, state “none”

NONE

(c) Attachments

Is a Supplemental Form 8 (Open Positions) attached?

NO

Date of disclosure:	19 June 2026
Contact name:	Anne Kochevar
Telephone number:	312-587-3849

Public disclosures under Rule 8 of the Code must be made to a Regulatory Information Service.

The Panel’s Market Surveillance Unit is available for consultation in relation to the Code’s disclosure requirements on [phone].

The Code can be viewed on the Panel’s website at www.thetakeoverpanel.org.uk.