ASX ASE Technology Holding Co Ltd

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

1 ASE Technology Holding Co., Ltd. October 28, 2021 ASE Technology Holding Third Quarter 2021 Earnings Release

2 Safe Harbor Notice This presentation contains "forward - looking statements" within the meaning of Section 27A of the United States Securities Act of 1933, as amended, and Section 21E of the United States Securities Exchange Act of 1934, as amended. Although these forward - looking statements, which may include statements regarding our future results of operations, financial condition or business prospects, are based on our own information and information from other sources we believe to be reliable, you should not place undue reliance on these forward - looking statements, which apply only as of the date of this press release. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “plan” and similar expressions, as they relate to us, are intended to identify these forward - looking statements in this press release. These forward - looking statements are necessarily estimates reflecting the best judgment of our senior management and our actual results of operations, financial condition or business prospects may differ materially from those expressed or implied by the forward - looking statements for reasons including, among others, risks associated with cyclicality and market conditions in the semiconductor or electronic industry; changes in our regulatory environment, including our ability to comply with new or stricter environmental regulations and to resolve environmental liabilities; demand for the outsourced semiconductor packaging, testing and electronic manufacturing services we offer and for such outsourced services generally; the highly competitive semiconductor or manufacturing industry we are involved in; our ability to introduce new technologies in order to remain competitive; international business activities; our business strategy; our future expansion plans and capital expenditures; the strained relationship between the Republic of China and the People’s Republic of China; general economic and political conditions; the recent shift in United States trade policies; possible disruptions in commercial activities caused by natural or human - induced disasters; fluctuations in foreign currency exchange rates; and other factors. For a discussion of these risks and other factors, please see the documents we file from time to time with the Securities and Exchange Commission, including the 2020 Annual Report on Form 20 - F filed on April 6, 2021.

3 Consolidated Statements of Comprehensive Income Quarterly Comparison (unaudited) (NT$ Million) Q3 / 2021 % Q2 / 2021 % Q3 / 2020 % QoQ YoY Net Revenues: ATM 88,791 58.9% 77,160 60.8% 69,497 56.4% 15% 28% EMS 61,116 40.6% 49,147 38.7% 53,126 43.1% 24% 15% Others 758 0.5% 619 0.5% 572 0.5% 22% 33% Total Net Revenues 150,665 100.0% 126,926 100.0% 123,195 100.0% 19% 22% Gross Profit 30,784 20.4% 24,804 19.5% 19,720 16.0% 24% 56% Operating Income (Loss) 18,426 12.2% 13,174 10.4% 9,141 7.4% 40% 102% Pretax Income (Loss) 18,474 12.3% 13,344 10.5% 9,014 7.3% 38% 105% Income Tax Benefit (Expense) (3,630) -2.4% (2,648) -2.1% (1,797) -1.5% Non-controlling Interest (668) -0.4% (358) -0.3% (505) -0.4% Net Income Attributable to Shareholders of the Parent 14,176 9.4% 10,338 8.1% 6,712 5.4% 37% 111% Basic EPS 3.29 2.40 1.57 37% 110% Diluted EPS 3.20 2.30 1.54 39% 108% Additional Commentary From Management 1&2 : Gross Profit excl. PPA expenses 31,716 21.1% 25,738 20.3% 20,607 16.7% 23% 54% Operating Profit excl. PPA expenses 19,620 13.0% 14,372 11.3% 10,281 8.3% 37% 91% Net Profit excl. PPA expenses 15,374 10.2% 11,510 9.1% 7,850 6.4% 34% 96% Basic EPS excl. PPA expenses 3.56 2.67 1.84 33% 94% 1 : PPA expenses are the P&L impacts from the accounting treatment of purchase price allocation in relation to the ASE/SPIL trans act ion, which resulted in increased asset values from purchase price premiums in PP&E, intangibles and right - of - use assets. The PPA exp enses excluded are related to depreciation, amortization and other expenses $ 1.15bn in 3Q21, $1.13bn in 2Q21 and $1.14bn in 3Q20. 2 : PPA expenses are the P&L impacts from the accounting treatment of purchase price allocation in relation to the USI/ Asteelflash transaction, which resulted in increased asset and liability values from purchase price premiums in PP&E , intangibles, right - of - use assets and deferred tax liability. The PPA expenses excluded are related to depreciation , amortization , other expenses, income tax benefit and non - controlling interest $ 0.06bn in 3Q21 and $ 0.05bn in 2Q21.

4 ATM Statements of Comprehensive Income Quarterly Comparison (unaudited) (NT$ Million) Q3 / 2021 % Q2 / 2021 % Q3 / 2020 % QoQ YoYNet Revenues: Packaging 75,221 83.5% 65,936 83.5% 58,417 81.3% 14% 29% Testing 13,416 14.9% 11,677 14.8% 12,351 17.2% 15% 9% Direct Material 1,429 1.6% 1,372 1.7% 1,020 1.4% 4% 40% Others 26 0.0% 3 0.0% 32 0.1% 767% -19% Total Net Revenues 90,092 100.0% 78,988 100.0% 71,820 100.0% 14% 25% Gross Profit 24,714 27.4% 20,210 25.6% 14,540 20.2% 22% 70% Operating Income (Loss) 15,631 17.3% 11,827 15.0% 6,809 9.5% 32% 130% Additional Commentary From Management 3 : Gross Profit excl. PPA expenses 25,594 28.4% 21,091 26.7% 15,427 21.5% 21% 66% Operating Profit excl. PPA expenses 16,761 18.6% 12,959 16.4% 7,949 11.1% 29% 111% 3 : PPA expenses are the P&L impacts from the accounting treatment of purchase price allocation in relation to the ASE/SPIL transaction, which resulted in increased asset values from purchase price premiums in PP&E, intangibles and right - of - use assets. The PPA expenses excluded are related to depreciation and amortization $1.13bn in both 3Q21 and 2Q21, and $ 1.14bn in 3Q20.

5 ATM Operations (unaudited) 13,334 15,082 14,540 16,478 18,007 20,210 24,714 66,209 69,516 71,820 72,752 73,767 78,988 90,092 20.1% 21.7% 20.2% 22.6% 24.4% 25.6% 27.4% 0% 10% 20% 30% 40% 0 20,000 40,000 60,000 80,000 100,000 Q1/20 Q2/20 Q3/20 Q4/20 Q1/21 Q2/21 Q3/21 NT$ Million Gross Profit Gross Margin Revenue

6 ATM Revenue by Application (unaudited) 54% 54% 53% 52% 50% 50% 51% 15% 14% 14% 14% 14% 14% 15% 31% 32% 33% 34% 36% 36% 34% 0% 20% 40% 60% 80% 100% Q1/20 Q2/20 Q3/20 Q4/20 Q1/21 Q2/21 Q3/21 Communication Computing Automotive, Consumer & Others

7 38% 38% 37% 35% 34% 33% 36% 36% 35% 37% 39% 40% 42% 39% 7% 7% 8% 9% 9% 8% 8% 17% 18% 17% 15% 15% 15% 15% 2% 2% 1% 2% 2% 2% 2% 0% 20% 40% 60% 80% 100% Q1/20 Q2/20 Q3/20 Q4/20 Q1/21 Q2/21 Q3/21 Material Testing Discrete and Other Wirebonding Bump/FC/WLP /SiP ATM Revenue by Type (unaudited)

8 EMS Operations Quarterly Comparison & Revenue By Application (unaudited ) (NT$ Million) Q3 / 2021 4 % Q2 / 2021 4 % Q3 / 2020 % QoQ YoY EMS Net Revenues 61,127 100.0% 49,154 100.0% 53,137 100.0% 24% 15% Gross Profit 5,883 9.6% 4,476 9.1% 5,147 9.7% 31% 14% Operating Income (Loss) 2,658 4.3% 1,273 2.6% 2,326 4.4% 109% 14% 36% 46% 40% 45% 39% 39% 38% 14% 12% 6% 4% 7% 10% 10% 33% 28% 40% 39% 33% 28% 33% 11% 10% 9% 8% 14% 16% 12% 6% 3% 4% 3% 5% 5% 5% 1% 1% 1% 2% 2% 2% 0% 20% 40% 60% 80% 100% Q1/20 Q2/20 Q3/20 Q4/20 Q1/21 Q2/21 Q3/21 Communication Computing & Storage Consumer Industrial Automotive Others 4 : PPA expenses are the P&L impacts from the accounting treatment of purchase price allocation in relation to the USI/ Asteelflash transaction, which resulted in increased asset and liability values from purchase price premiums in PP&E , intangibles and right - of - use assets. The PPA expenses excluded are related to depreciation and amortization $ 0.06bn in 3Q21 and $ 0.07bn in 2Q21.

9 Key Balance Sheet Items & Indices (unaudited) (NT$ Million) Sept. 30, 2021 Jun. 30, 2021 Cash and cash equivalent 53,419 52,987 Financial assets - current 4,133 4,492 Financial assets - non current & investments - equity method 20,915 19,982 Property, plant & equipment 252,384 244,861 Total assets 650,467 611,857 Short-term loans 36,610 40,460 Current portion of bonds payable 3,699 3,699 Current portion of long-term loans 2,840 4,864 Bonds payable 48,498 48,474 Long-term loans & long-term bills payable 137,015 106,124 Total interest bearing debts 235,326 209,723 Total liabilities 399,628 357,352 Total equity (Including non-controlling interest) 250,839 254,505 Quarterly EBITDA 32,655 27,350 Current ratio 1.35 1.30 Net debt to equity ratio 0.71 0.60

11 Fourth Quarter 2021 Outlook* Based on our current business outlook and exchange rate assumptions, management projects overall performance for the fourth quarter of 2021 to be as follows: • In US dollar terms, our ATM 4th quarter 2021 business level should be similar to our 3rd quarter 2021 business level; • Our ATM 4th quarter 2021 gross margin should be similar to our 3rd quarter 2021 gross margin ; • In USD terms, our EMS 4th quarter 2021 business level should come close to our 4th quarter 2020 levels; • Our EMS 4th quarter 2021 operating margin should come close to our 3rd quarter 2021 operating margin . *: Due to the impact of the COVID - 19 outbreak, our outlook continues to be subject to a higher degree of risk. The information provided is done so as a reference of our current view as of the date of this presentation. Our business, financial condition an d results of operations are of greater adverse risk; and, as a result, there may be a higher likelihood of material variances b etw een our expected and actual results .

12 www.aseglobal.com Thank You

13 Appendix 1 Consolidated Statements of Comprehensive Income ( unaudited) (NT$ Thousand) Q1/2020 Q2/2020 Q3/2020 Q4/2020 FY/2020 Q1/2021 Q2/2021 Q3/2021 Revenues 97,357,155 107,548,773 123,195,399 148,877,383 476,978,710 119,469,784 126,926,346 150,664,816 COGS 81,201,507 88,739,372 103,475,591 125,577,972 398,994,442 97,583,415 102,122,197 119,880,851 PPA under COGS 1,049,113 887,560 886,817 884,479 3,707,969 1,024,525 933,946 931,880 Gross profit 16,155,648 18,809,401 19,719,808 23,299,411 77,984,268 21,886,369 24,804,149 30,783,965 Gross profit excl. PPA 17,204,761 19,696,961 20,606,625 24,183,890 81,692,237 22,910,894 25,738,095 31,715,845 OPEX 10,092,942 10,382,863 10,578,715 12,053,666 43,108,186 10,977,703 11,630,191 12,357,669 PPA under OPEX 253,185 253,185 253,185 253,185 1,012,742 269,154 263,543 262,097 Operating income 6,062,706 8,426,538 9,141,093 11,245,745 34,876,082 10,908,666 13,173,958 18,426,296 Operating income excl. PPA 7,365,004 9,567,283 10,281,095 12,383,410 39,596,792 12,202,345 14,371,447 19,620,273 Non Op gain/(loss) (826,352) 452,430 (126,617) 1,358,135 857,596 271,633 170,726 48,235 PPA under Non Op gain/ (loss) 30,283 13,617 (1,659) 57,724 99,966 43,225 2,813 39,929 Non Op gain/ (loss) excl. PPA (796,069) 466,047 (128,276) 1,415,859 957,562 314,858 173,539 88,164 Pretax income 5,236,354 8,878,968 9,014,477 12,603,881 35,733,680 11,180,299 13,344,684 18,474,530 PPA under Pretax income 1,332,581 1,154,363 1,138,344 1,195,389 4,820,676 1,336,904 1,200,302 1,233,906 Pretax income excl. PPA 6,568,935 10,033,331 10,152,821 13,799,270 40,554,356 12,517,203 14,544,986 19,708,436 Tax expenses 1,175,024 1,645,554 1,797,149 1,839,173 6,456,900 2,451,096 2,648,128 3,630,545 PPA under Tax expense 0 0 0 0 0 (38,471) (16,250) (20,612) Tax expense excl. PPA 1,175,024 1,645,554 1,797,149 1,839,173 6,456,900 2,489,567 2,664,378 3,651,157 Non-controlling interest 162,700 295,819 504,607 720,674 1,683,800 252,076 358,136 667,705 PPA under Non-controlling interest 0 0 0 0 0 30,714 12,788 15,661 Non-controlling interest excl. PPA 162,700 295,819 504,607 720,674 1,683,800 282,790 370,924 683,366 Net income attributable to shareholders of the parent 3,898,630 6,937,595 6,712,721 10,044,034 27,592,980 8,477,127 10,338,420 14,176,280 PPA expenses under Net income attributable to shareholders of the 1,332,581 1,154,363 1,138,344 1,195,389 4,820,676 1,267,719 1,171,264 1,197,633 Net income attributable to shareholders of the parent excl. PPA 5,231,211 8,091,958 7,851,065 11,239,423 32,413,656 9,744,846 11,509,684 15,373,913 Total PPA expenses 1,332,581 1,154,363 1,138,344 1,195,389 4,820,676 1,298,433 1,184,052 1,213,294 Basic EPS (NT$) 0.92 1.63 1.57 2.35 6.47 1.97 2.40 3.29 Basic EPS (NT$) excl. PPA 1.23 1.90 1.84 2.63 7.60 2.26 2.67 3.56 Diluted EPS (NT$) 0.89 1.60 1.54 2.30 6.31 1.92 2.30 3.20 Diluted EPS (NT$) excl. PPA 1.21 1.87 1.80 2.58 7.44 2.21 2.57 3.47