Announced on behalf of CTBC Securities regarding changes in accounting estimates after the beginning of FY 2027(Supplement to the 2026/09/21 announcement.)

1.Date of board of directors resolution:2026/09/21
2.Nature of the change:Change in accounting estimates.
3.Reason for the change:CTBC Securities has reassessed certain buildings,
equipment, and intangible assets based on their actual usage status,
with reference to industry peers and the experience of its parent company.
The reassessment indicates that the actual useful lives of certain
buildings, equipment, and intangible assets exceed their originally
estimated useful lives. To reflect the actual useful lives and allocate
costs reasonably, the company plans to extend the useful lives of certain
buildings, equipment, and intangible assets and revise their estimated
residual values to zero.
4.Each line item affected and the projected effect for the accounting year
 preceding the accounting year changed by retrospective application of the
 accounting policy change:NA.
5.The actual effect on the opening balance of retained earnings
for the last accounting year:NA.
6.If the decided effect is impracticable, specify the reasons
why retrospective application is impracticable, and how and from
when the accounting policy change will be applied:NA.
7.If the decided effect is impracticable, the opinion provided
by the CPA about the effect of the audit opinion for the
accounting year preceding the accounting change:NA.
8.Opinion expressed by the CPA regarding itemized analysis of reasonableness:
According to the review opinion issued by the CPA, there is no
inconsistency identified in the accounting treatment related to the
changes in accounting estimates.
9.Objection or reservation opinion from the independent directors:None.
10.Countermeasures:None.
11.Any other matters that need to be specified:This matter was approved
by the competent authority and became effective on 2026/11/02.