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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

15 May 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:

15,391,680

3.66

 

 

(2) Cash-settled derivatives:

 

 

 

 

 

(3) Stock-settled derivatives (including options) and agreements to purchase/sell:

 

 

 

 

 

TOTAL:

15,391,680

3.66

 

 

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

68.84

2.8575

10p Ordinary

Sale

186.41

2.8575

10p Ordinary

Sale

382.26

2.8575

10p Ordinary

Sale

123.00

2.8575

10p Ordinary

Sale

156.88

2.8575

10p Ordinary

Sale

573.38

2.8575

10p Ordinary

Sale

35.91

2.8575

10p Ordinary

Sale

97.69

2.8575

10p Ordinary

Sale

87.42

2.8575

10p Ordinary

Sale

123.13

2.8575

10p Ordinary

Sale

70.81

2.8575

10p Ordinary

Sale

1,055.75

2.8575

10p Ordinary

Sale

300.34

2.8575

10p Ordinary

Sale

112.52

2.8575

10p Ordinary

Sale

156.25

2.8575

10p Ordinary

Sale

35.50

2.8575

10p Ordinary

Sale

399.77

2.8575

10p Ordinary

Sale

130.76

2.8575

10p Ordinary

Sale

647.81

2.8575

10p Ordinary

Sale

909.21

2.8575

10p Ordinary

Sale

30.84

2.8575

10p Ordinary

Sale

77.29

2.8575

10p Ordinary

Sale

640.06

2.8575

10p Ordinary

Sale

289.13

2.8575

10p Ordinary

Sale

347.90

2.8575

10p Ordinary

Sale

101.13

2.8575

10p Ordinary

Sale

205.94

2.8575

10p Ordinary

Sale

547.56

2.8575

10p Ordinary

Sale

594.05

2.8575

10p Ordinary

Sale

111.88

2.8575

10p Ordinary

Sale

20.72

2.8575

10p Ordinary

Sale

385.87

2.8575

10p Ordinary

Sale

280.82

2.8575

10p Ordinary

Sale

494.49

2.8575

10p Ordinary

Sale

304.78

2.8575

10p Ordinary

Sale

161.98

2.8575

10p Ordinary

Sale

478.69

2.8575

10p Ordinary

Sale

3.49

2.8575

10p Ordinary

Sale

151.11

2.8575

10p Ordinary

Sale

70.67

2.8575

10p Ordinary

Sale

410.39

2.8575

10p Ordinary

Sale

141.62

2.8575

10p Ordinary

Sale

225.51

2.8575

10p Ordinary

Sale

207.08

2.8575

10p Ordinary

Sale

118.01

2.8575

10p Ordinary

Sale

394.10

2.8575

10p Ordinary

Sale

279.23

2.8575

10p Ordinary

Sale

481.00

2.8575

10p Ordinary

Sale

296.98

2.8575

10p Ordinary

Sale

193.75

2.8575

10p Ordinary

Sale

108.56

2.8575

10p Ordinary

Sale

71.70

2.8575

10p Ordinary

Sale

2,247.51

2.8575

10p Ordinary

Sale

1,588.51

2.8575

10p Ordinary

Sale

576.93

2.8556

10p Ordinary

Sale

1,562.20

2.8556

10p Ordinary

Sale

3,203.56

2.8556

10p Ordinary

Sale

1,030.79

2.8556

10p Ordinary

Sale

1,314.74

2.8556

10p Ordinary

Sale

4,805.24

2.8556

10p Ordinary

Sale

300.92

2.8556

10p Ordinary

Sale

818.72

2.8556

10p Ordinary

Sale

732.60

2.8556

10p Ordinary

Sale

1,031.87

2.8556

10p Ordinary

Sale

593.44

2.8556

10p Ordinary

Sale

8,847.72

2.8556

10p Ordinary

Sale

2,516.99

2.8556

10p Ordinary

Sale

942.97

2.8556

10p Ordinary

Sale

1,309.47

2.8556

10p Ordinary

Sale

297.47

2.8556

10p Ordinary

Sale

3,350.31

2.8556

10p Ordinary

Sale

1,095.80

2.8556

10p Ordinary

Sale

5,428.96

2.8556

10p Ordinary

Sale

7,619.64

2.8556

10p Ordinary

Sale

258.46

2.8556

10p Ordinary

Sale

647.72

2.8556

10p Ordinary

Sale

5,364.00

2.8556

10p Ordinary

Sale

2,423.08

2.8556

10p Ordinary

Sale

2,915.59

2.8556

10p Ordinary

Sale

847.56

2.8556

10p Ordinary

Sale

1,725.88

2.8556

10p Ordinary

Sale

4,588.83

2.8556

10p Ordinary

Sale

4,978.40

2.8556

10p Ordinary

Sale

937.60

2.8556

10p Ordinary

Sale

173.63

2.8556

10p Ordinary

Sale

3,233.80

2.8556

10p Ordinary

Sale

2,353.42

2.8556

10p Ordinary

Sale

4,144.05

2.8556

10p Ordinary

Sale

2,554.24

2.8556

10p Ordinary

Sale

1,357.51

2.8556

10p Ordinary

Sale

4,011.65

2.8556

10p Ordinary

Sale

29.26

2.8556

10p Ordinary

Sale

1,266.39

2.8556

10p Ordinary

Sale

592.25

2.8556

10p Ordinary

Sale

3,439.32

2.8556

10p Ordinary

Sale

1,186.87

2.8556

10p Ordinary

Sale

1,889.86

2.8556

10p Ordinary

Sale

1,735.42

2.8556

10p Ordinary

Sale

988.94

2.8556

10p Ordinary

Sale

3,302.73

2.8556

10p Ordinary

Sale

2,340.11

2.8556

10p Ordinary

Sale

4,031.00

2.8556

10p Ordinary

Sale

2,488.87

2.8556

10p Ordinary

Sale

1,623.76

2.8556

10p Ordinary

Sale

909.79

2.8556

10p Ordinary

Sale

600.92

2.8556

10p Ordinary

Sale

18,835.25

2.8556

10p Ordinary

Sale

13,312.53

2.8556

10p Ordinary

Sale

4,233.00

2.8575

10p Ordinary

Sale

8,096.00

2.8575

10p Ordinary

Sale

52,265.00

2.8556

10p Ordinary

Sale

51,052.00

2.8556

10p Ordinary

Sale

4,015.00

2.8575

10p Ordinary

Sale

1,607.00

2.8575

10p Ordinary

Sale

22,417.00

2.8556

10p Ordinary

Sale

24,692.00

2.8556

10p Ordinary

Sale

38,672.00

2.8556

10p Ordinary

Sale

52,731.00

2.8556

10p Ordinary

Sale

23,510.00

2.8556

10p Ordinary

Sale

13,712.00

2.8575

10p Ordinary

Sale

19,655.00

2.8575

10p Ordinary

Sale

13,921.00

2.8575

10p Ordinary

Sale

135,962.00

2.8556

10p Ordinary

Sale

145,415.00

2.8556

(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:

18 May 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 +44 (0)20 7638 0129.

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

Category Code: RET
Sequence Number: 1577398
Time of Receipt (offset from UTC): 20260518T134541+0100

Contacts

Driehaus Capital Management LLC

Driehaus Capital Management LLC

LSE:SNR

Release Versions

Contacts

Driehaus Capital Management LLC

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