RNS Number : 1681G
Quantum Data Energy PLC
04 November 2025
Quantum Data Energy PLC
(formerly Mast Energy Developments PLC)
(Incorporated in England and Wales)
(Registration Number: 12886458)
LEI :213800HFVHGJ9YGO9F71
Share code on the LSE: MAST
ISIN: GB00BNG90H86
('Quantum Data' or 'the Company')
Dated: 4 November 2025
Quantum Data Energy PLC
TR-1: Standard form for notification of major holdings
1. Issuer Details
ISIN
GB00BNG90H86
Issuer Name
MAST ENERGY DEVELOPMENTS PLC
UK or Non-UK Issuer
UK
2. Reason for Notification
An acquisition or disposal of voting rights
3. Details of person subject to the notification obligation
Name
Peel Hunt LLP
City of registered office (if applicable)
London
Country of registered office (if applicable)
United Kingdom
4. Details of the shareholder
Full name of shareholder(s) if different from the person(s) subject to the notification obligation, above
City of registered office (if applicable)
Country of registered office (if applicable)
5. Date on which the threshold was crossed or reached
31-Oct-2025
6. Date on which Issuer notified
03-Nov-2025
7. Total positions of person(s) subject to the notification obligation
% of voting rights attached to shares (total of 8.A)
% of voting rights through financial instruments (total of 8.B 1 + 8.B 2)
Total of both in % (8.A + 8.B)
Total number of voting rights held in issuer
Resulting situation on the date on which threshold was crossed or reached
10.246828
0.000000
10.246828
3255000
Position of previous notification (if applicable)
Under 10%
0.000000
Under 10%
8. Notified details of the resulting situation on the date on which the threshold was crossed or reached
8A. Voting rights attached to shares
Class/Type of shares ISIN code(if possible)
Number of direct voting rights (DTR5.1)
Number of indirect voting rights (DTR5.2.1)
% of direct voting rights (DTR5.1)
% of indirect voting rights (DTR5.2.1)
GB00BNG90H86
3255000
0
10.246828
0.000000
Sub Total 8.A
3255000
10.246828%
8B1. Financial Instruments according to (DTR5.3.1R.(1) (a))
Type of financial instrument
Expiration date
Exercise/conversion period
Number of voting rights that may be acquired if the instrument is exercised/converted
% of voting rights
Sub Total 8.B1
8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b))
Type of financial instrument
Expiration date
Exercise/conversion period
Physical or cash settlement
Number of voting rights
% of voting rights
Sub Total 8.B2
9. Information in relation to the person subject to the notification obligation
1. Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuer.
Ultimate controlling person
Name of controlled undertaking
% of voting rights if it equals or is higher than the notifiable threshold
% of voting rights through financial instruments if it equals or is higher than the notifiable threshold
Total of both if it equals or is higher than the notifiable threshold
10. In case of proxy voting
Name of the proxy holder
The number and % of voting rights held
The date until which the voting rights will be held
11. Additional Information
12. Date of Completion
03-Nov-2025
13. Place Of Completion
London
TR-1: Standard form for notification of major holdings
1. Issuer Details
ISIN
GB00BNG90H86
Issuer Name
MAST ENERGY DEVELOPMENTS PLC
UK or Non-UK Issuer
UK
2. Reason for Notification
An acquisition or disposal of voting rights
3. Details of person subject to the notification obligation
Name
Peel Hunt LLP
City of registered office (if applicable)
London
Country of registered office (if applicable)
United Kingdom
4. Details of the shareholder
Full name of shareholder(s) if different from the person(s) subject to the notification obligation, above
City of registered office (if applicable)
Country of registered office (if applicable)
5. Date on which the threshold was crossed or reached
03-Nov-2025
6. Date on which Issuer notified
04-Nov-2025
7. Total positions of person(s) subject to the notification obligation
% of voting rights attached to shares (total of 8.A)
% of voting rights through financial instruments (total of 8.B 1 + 8.B 2)
Total of both in % (8.A + 8.B)
Total number of voting rights held in issuer
Resulting situation on the date on which threshold was crossed or reached
Below 10%
0.000000
Below 10%
Below 10% of shares in issue
Position of previous notification (if applicable)
10.246828
0.000000
10.246828
8. Notified details of the resulting situation on the date on which the threshold was crossed or reached
8A. Voting rights attached to shares
Class/Type of shares ISIN code(if possible)
Number of direct voting rights (DTR5.1)
Number of indirect voting rights (DTR5.2.1)
% of direct voting rights (DTR5.1)
% of indirect voting rights (DTR5.2.1)
GB00BNG90H86
Below 10% of shares in issue
Below 10%
Sub Total 8.A
Below 10% of shares in issue
Below 10%
8B1. Financial Instruments according to (DTR5.3.1R.(1) (a))
Type of financial instrument
Expiration date
Exercise/conversion period
Number of voting rights that may be acquired if the instrument is exercised/converted
% of voting rights
Sub Total 8.B1
8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b))
Type of financial instrument
Expiration date
Exercise/conversion period
Physical or cash settlement
Number of voting rights
% of voting rights
Sub Total 8.B2
9. Information in relation to the person subject to the notification obligation
1. Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuer.
Ultimate controlling person
Name of controlled undertaking
% of voting rights if it equals or is higher than the notifiable threshold
% of voting rights through financial instruments if it equals or is higher than the notifiable threshold
Total of both if it equals or is higher than the notifiable threshold
10. In case of proxy voting
Name of the proxy holder
The number and % of voting rights held
The date until which the voting rights will be held
11. Additional Information
12. Date of Completion
04-Nov-2025
13. Place Of Completion
London
ENDS
This announcement contains inside information for the purposes of the UK version of the Market Abuse Regulation (EU No. 596/2014) as it forms part of United Kingdom domestic law by virtue of the European Union (Withdrawal) Act 2018 ('UK MAR'). Upon the publication of this announcement, this inside information is now considered to be in the public domain.
Pieter Krügel
info@med.energy
Mast Energy Developments PLC
CEO
Guy Wheatley, CFA
+44 (0)203 411 7773
Fortified Securities
Corporate Broker
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