伯恩斯坦-日本半导体：硅晶圆短缺在望但前提假设风险极高-Japan Semis：Silicon wafer shortage in sightbut with a highly risky assumption-20260420

20April2026

JapanSemiconductors

JapanSemis:Siliconwafershortageinsight...butwithahighlyriskyassumption

DavidDai,CFA

+85229185704

david.dai@

JackLin

+85221232683

jack.lin@

JuhoHwang

+85221232632

juho.hwang@

CarmineMilano

+442077621857

ano@

Weforecastglobalex-China12”rawsiliconwaferdemandtogrowat11%CAGRinthenextthreeyears,drivenbyincreasedmemoryusageandwafer-to-waferbondingtechnologies.DRAMwaferbenefitsfromHBMconsuming3-4xwafersperbitcomparedtoDDR5,NANDadoptingwafer-to-waferbonding(CBA)toseparatelyfabricatethelogicchipsandmemorycellondifferentwafers,andLogicseesrapidgrowthofadvancedlogiccapacityandadoptionofBacksidePower(BSPDN)uses2wafersperchip.Ourrawsiliconwafersupply-demandmodelisavailablefordownloadhere.

Inthemeanwhile,ex-Chinasiliconwafersupplyisonlygrowingat3%CAGR.Theglobalex-Chinasiliconwafersupplyisconcentratedwithtop5taking>90%share.As

theindustryisinoversupplypost-COVID,thesupplyexpansionisverylimited.Theend

customersinventoryishighat~4months,twiceasmuchasnormallevel.Utilizationofrawwaferproducersareonlyat~85%.Thewillingnesstoexpandcapacityislow,andSUMCOjustcanceledaplantobuildanewfactoryin2029.Eveniftheydecidetorestart,ittakes3yearstobuildanewfactory.

Siliconwafershortageinsight?Withdemandgrowth,weexpecttheendcustomers

waferinventorytodropsubstantiallythisyear,andnormalizesto2monthsbytheendof

theyearorearlynextyear.Afterinventorynormalizes,anddemandgrows~20%from

2025to2027,andit’seasytodrawtheconclusionthatwafershortageiscomingin2027,leadingto>100%utilization,pricehikes,newfavorableLTAs,marginexpansion…whichexplainsthestronginteresttolongwafersuppliersnow.Wecansee12%oversupplyin

2025turninginto7%shortagein2028,assuming...

…Chinadoesn’tspoiltheparty?TheaboveanalysisignoresChinawafersuppliers,

whichis28%ofglobalsupplyandincreasingcapacityby77%in3years.ThebullviewisthatChinesesupplierswillnotbeabletoaddresstheglobalmarketasthequalityislower,leadingtolowercustomeryield.ButtheyareperfectlyabletomeetthedemandofNANDandmaturelogicwhichare~60%ofwaferdemandandarenotdemandinginwaferquality.AssumingChinaincreasesexportofsiliconwafers,theglobalsuppliers’UTRwillremain

<95%inthenext3years.

SUMCOtrademaybeOK…butonlyasatrade.SUMCOpricesurged45%YTDdue

tothecycleturnargument,andglobalpeers(Shin-Etsu,GlobalWafers,Siltronic,allnot

covered)showedsametrend.Nowtradingat1.32xP/B,thereisprobablystillsomeupsidetogoforSUMCO(bullsexpect1.5-2x),especiallywhentheupcomingearningshows

inventorystartingtodropsignificantly.Butfundamentally,thethreatfromChinesesuppliersisreal,andinvestorsshouldn’toverstaythewelcome.WerateSUMCOMarket-Perform,

PT=¥1,530.00.

SeetheDisclosureAppendixofthisreportforrequireddisclosures,analystcertificationsandotherimportantinformation.Alternatively,visitourGlobalResearchDisclosureWebsite.

FirstPublished:19Apr202620:30UTCCompletionDate:19Apr202616:29UTC

DavidDai,CFA+85229185704

david.dai@

20April2026

BERNSTEINTICKERTABLE

17Apr2026

TTM

ReportedEPSReportedP/E(x)

Ticker

Rating

Cur

Closing Price

Price

Target

Rel.

Perf.

Cur2025A2026E2027E

2025A2026E2027E

3436.JP(SUMCO)JPL

M

JPY

2,095.00

2,429.81

1,530.00

86.2%

JPY(33.61)(49.22)42.38

(62.3)(42.6)49.4

O-Outperform,M-Market-Perform,U-Underperform,NR-NotRated,CS-CoverageSuspendedSource:Bloomberg,Bernsteinestimatesandanalysis.

INVESTMENTIMPLICATIONS

SUMCO:WerateSUMCOMarket-PerformwithapricetargetofJPY1,530.00.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP2

DavidDai,CFA+85229185704

david.dai@

20April2026

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP3

TableOfContents

Globalsiliconwaferdemandseeslow-teens%growth 3

Globalex-Chinasiliconwafersupplyonlygrowsat3%CAGR,whileChinaexpandsmuchfaster 5

IfChinesesuppliersstayinChina,it’seasytoseewafershortageinex-China butthat’sabigIF...................................................7

WilltheChinesesuppliersbeabletoaddresstheoverseamarket? 8

Stockimplications:probablygoodasatradefornow butit’sjustatrade............................................................................................10

DETAILS

We’vecontinuouslyupdatedtherawsiliconwaferspace(JapanSemis:SiliconWafer-RisingChinesesupplylimitsgrowthfor

internationalincumbents;GlobalSemis:RiseoftheChinesewafersuppliers;SUMCO:Overhypedexpectationsresetaftersharecorrection;upgradingtoMarket-Perform).Inthisreport,weupdateourlatestviewsofthesiliconwafersupplyanddemandinthenextthreeyears.Keytakeaways:

•Globalex-China12”siliconwaferdemand(12”wafersonlyunlessotherwisespecified)isexpectedtogrowat11%CAGRoverthenextthreeyears,drivenbyrisingmemorycontentandwafer-to-waferbondingtechnologiessuchasCMOSDirectlyBondedtoArray(CBA)andBacksidePowerDeliveryNetwork(BSPDN).

•Meanwhile,ex-Chinasiliconwafersupplyisexpectedtogrowatonly3%CAGR,withcurrentutilizationremaininglowat~85%duetoelevatedend-customerinventoryof~4months.

•Itiseasytoconcludethatinventorycouldnormalizethisyearandwaferoversupplycouldturnintoshortagein2027,drivingutilizationto>100%,alongsidepricehikes,morefavorablelong-termagreements(LTAs),andmarginexpansion.

•Butdon’tforgetChinawhichisincreasingcapacityby77%overthenextthreeyears.OnceChinarampsupsiliconwaferexports,globalsuppliers’utilizationislikelytoremain<95%overthenextthreeyears.

Detailsbelow,andourrawsiliconwafersupply-demandmodelisavailablefordownıoadhere.

GLOBALSILICONWAFERDEMANDSEESLOW-TEENS%GROWTH

•Weforecastglobalsiliconwaferdemandtogrowat12%2025-2028CAGR(Exhibit1),drivenby:

•DRAM:GlobalDRAMwafercapacityincreaseisthebiggestgrowthdriver,especiallyHBMwhichconsumes3-4xwafersperbitcomparedtoDDR5(Exhibit2).

•NAND:WhileNANDwafershipmentsarenotgrowingsignificantly,NANDisrapidlyadoptingwafer-to-waferbonding(CBA),whichseparatelyfabricateslogicandmemorycellsondifferentwafersbeforebondingthemtogether.We

explainedthistechnologyinGlobalSemis:NANDhybridbonding-thenextfrontierofadvancedpackaging.Assuch,NANDwaferusageisgrowingata14%CAGR,wellabovewaferoutputgrowth(Exhibit3).

•Logic:Whilematurelogicisseeinglimitedgrowth,advancedlogicwaferusageisgrowingrapidlyonAIdemand,andBacksidePower(BSPDN)requires2wafersperchip(Exhibit4).ThiswasexplainedinGlobalSemis:BacksidePower-AdvancedpackagingtoextendMoore'sLaw.

•LookingatChinaandex-Chinaseparately,Chinawaferdemandgrowthismuchhigherat+18.2%,whileex-Chinademandgrowthremainshealthyat+11%(Exhibit5andExhibit6).ThisismostlydrivenbyChina’sefforttolocalizesemiconductorproduction,whichcouldbeevenfasterthanwhatweseetoday.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP4

EXHIBIT1:2017-2028E:Global300mmwaferdemand

mwpm

2017-28E:Global300mmwaferdemand

1220%

910%

60%

3-10%

0-20%

DRAM

LogicfoundryYoY

NAND

IDM&Others

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT3:2023-2028ENANDRawWaferDemand:W2W(CBA)vs.Others

2023-2028ENANDRawWaferDemand:

W2W(CBA)vs.Others

kwpm

2%

0%0%

0

2023202420252026E2027E2028E

NormalNANDNANDCBA

28%

18%

9%

30%

25%

20%

15%

10%

5%

0%

2,000

1,500

1,000

500

NANDCBAas%oftotalNANDrawwaferdemand

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT2:2023-2028EDRAMRawWaferDemand:AIvs.Others

kwpm

2023-2028EDRAMRawWaferDemand:AIvs.Others

48%49%

3,00050%40%

2,50040%

2,000

30%

1,50020%

20%

1,00010%

5002%10%

00%

2023202420252026E2027E2028E

ConventionalDRAM

DRAMinAIServer

HBM

——AIas%oftotalDRAMrawwaferdemand

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT4:2023-2028ELogicRawWaferDemand:BSPDNvs.Others

2023-2028ELogicRawWaferDemand:

BSPDNvs.Others

kwpm

5%

3%

2%

0%0%0%

NormalLogic

BSPDN

BSPDNas%oftotalLogicrawwaferdemand

4,000

3,000

2,000

1,000

0

6%

5%

4%

3%

2%

1%

0%

2023202420252026E2027E2028E

Source:Companydisclosures,SEMI,Gartner,Bernsteinestimatesandanalysis.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP5

EXHIBIT5:RawWaferDemandinChina

RawWaferDemandinChina

kwpm

120%

100%

80%

60%

40%

20%

0%

3,500

3,000

2,500

2,000

1,500

1,000

500

0

ChinadomesticForeignfabsinChinaYoY

Source:Companydisclosures,Bernsteinestimatesandanalysis.

EXHIBIT6:RawWaferDemandinGlobalMarketexcludingChina

kwpm

RawWaferDemandinGlobalMarket

excludingChina

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

30%

20%

10%

0%

-10%-20%

-30%

Non-ChinaYoY

Source:Companydisclosures,SEMI,Bernsteinestimatesandanalysis.

GLOBALEX-CHINASILICONWAFERSUPPLYONLYGROWSAT3%CAGR,WHILECHINAEXPANDSMUCHFASTER

•Weforecastglobalex-Chinawafersupplytogrowat3%2025-2028CAGR(Exhibit7).

•Globalex-Chinasiliconwafersupplyishighlyconcentrated,withthetop5suppliersaccountingfor90+%ofmarket

share.Post-COVIDoversupplyhassuppressedcapacityexpansionplansacrosstheboard,withmostsupplierspivotingtowardtechnologyupgradesandutilizationrecoveryratherthannewgreenfieldbuilds.Therefore,supplyexpansionofglobalvendorsremainslimited.

•GlobalWafers(6488.TT,notcovered):GlobalWafersistheonlyonewithsizableprojects,dedicatedtohaving600kwpmcapacityintheUSwithgovernmentsubsidyreceived.Itopeneditsnew$3.5bn300mmfabinSherman,TexasinMay

2025,thefirstadvancedhigh-volume300mmsiliconwaferfacilityintheUS.Thecompanyisentitledtoupto$406m

inCHIPSActgrantsforitsTexasandMissouri(SOIwafers)projects,ofwhich$200mwasreceivedinmid-2025,with

thebalanceallocatedinphasestiedtoproductionmilestones.GlobalWafershasannouncedanadditional$4bnU.S.

investmentforaPhase2expansion,andhasalsoenteredintoasupplyagreementwithApplefor300mmwafersfromitsTexasplant.

•SUMCO:SUMCOadded300mmcapacityin2025-26,buthassincereversedcourseonfurtherexpansion,canceling/delayingtheconstructionoftwonew300mmsiliconwaferplantsoriginallyplannedforSagaPrefecture(Imariand

Yoshinogari),projectsthatwerefirstannouncedin2021.Thecompany'sMETIsubsidywasconsequentlyreducedfromtheoriginallyplannedJPY75bntoJPY19.3bn,reflectingthedownscaledambition.Goingforward,SUMCOwillfocusontechnologyupgradesandequipmentimprovementsatexistingplantstoimprovecapabilityforleading-edgeproducts,ratherthanincreasingvolume.

•Shin-Etsu(4063.JP,notcovered)andSiltronic(WAF.GR,notcovered)havenotyetannouncedanyfurtherexpansion

planon300mmsiliconwafer.Siltronichasanew300mmfactoryinSingaporethatinauguratedin2024,butwouldrampslowlyacrossseveralyears.SKSiltron(private)hasbeenexpanding12-inchwafercapacityatitsGumicomplexsince2022,withfull-scaleoperationsatthenewfactorytargetingcommencementfromJuly2026,subjecttosecuringKRW

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP6

500bninNationalGrowthFundsupport.

•Ontheotherhand,Chinasupplyisexpandingrapidlyat21%CAGR2025-2028(Exhibit8).

•NationalSiliconIndustryGroup(NSIG,688126.CH,notcovered):NSIGisoneofChina'slargest12-inchsiliconwafersuppliers,with~850Kkwpmof300mmcapacityasof2025,andplanstogrowbeyond1.2mnkwpmwithinthenextthreeyears.

•Eswin(688783.CH,notcovered):Eswinisevenmoreaggressive:startingfrom~800Kkwpmasof2025,itistargeting

1.8+mnkwpmwithinthenextthreeyearsacrossitsexistingXi'anbase,anewPhaseIIXi'anfacility,andathirdplantannouncedinWuhaninDecember2025.Tofinanceitsexpansion,EswinwentpubliconShanghaiSTARMarketinOctober2025,raisingCNY4.6bn.

•Overall,China’srawwafercapacityisalready28%ofglobaltotalin2025,andwillbe39%in2028(Exhibit9andExhibit10).

•DuetorapidgrowthofChinacapacity,theglobalsiliconwafersupplyisgrowingat8.7%CAGR,notmuchslowerthanthedemandgrowth.

EXHIBIT7:Global(excl.China)12’’rawwafersupply

Global(excl.China)12''rawwafersupply

mwpm

10

9

8

7

6

5

4

3

2

1

0

14%

12%

10%

8%

6%

4%

2%

0%

YoY

Sumco

SKSiltron

GlobalWafers

Others

ShinEtsu

SiltronicYoY

AllstocksnotcoveredexceptforSKSiltron(private)andSUMCO.

Source:Companydisclosures,SEMI,Bernsteinestimatesandanalysis.

EXHIBIT8:China12''RawWaferSupply

China12''RawWaferSupply

mwpm

150%

120%

90%

60%

30%

0%

7

6

5

4

3

2

1

0

NSIGEswin

TCLZhonghuanLionMicro

ZhongxinGrinm

ShanghaiASTYoY

Allstocksnotcovered.

Source:Companydisclosures,Bernsteinestimatesandanalysis.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP7

EXHIBIT9:Global12''RawWaferCapacityandChinaShare

Global12''RawWaferCapacityandChinaShare

0%

GlobalSuppliersChinaSuppliers

26%28%32%35%39%

74%72%68%65%61%

2%3%

98%97%

100%

80%

60%

40%

20%

20%

80%

8%

92%

15%

85%

Source:Companydisclosures,Bernsteinestimatesandanalysis.

EXHIBIT10:Global12''RawWaferShipmentandChinaShare

Global12''RawWaferShipmentandChina

0%

GlobalSuppliersChinaSuppliers

1%2%5%

99%98%95%

25%29%

75%71%

33%37%

67%63%

9%13%

91%87%

100%

80%

60%

40%

20%

19%

81%

Share

Source:Companydisclosures,SEMI,Bernsteinestimatesandanalysis.

IFCHINESESUPPLIERSSTAYINCHINA,IT’SEASYTOSEEWAFERSHORTAGEINEX-CHINA…BUTTHAT’SABIGIF

•Chinesesuppliersarerelativelynewtothemarket,havingenteredonlyin2019.

•ThecurrentmarketsituationisthatChinesesuppliersmainlyfulfillsdomesticdemand.Theyexportwafersaswell,butthosearemainlytestwafersinsteadofprimewafersforproduction.AssumingChinadoesnotaddressoverseasdemandgrowthanytimesoon(bullcase),Chinesesuppliers’shipmentgrowthwouldtrackChinesecapacitygrowth,implyingex-Chinawafersuppliers’utilizationreaches97%in2027and107%in2028,resultinginasevereshortage(Exhibit11andExhibit12).

•However,webelieveChinesesuppliersarescalingrapidlyandwillbeabletoserveglobaldemand,especiallyinashortagescenario.

•AssumingChinesesuppliersraiseproductionutilizationto85%in2028(ourbasecase),stillslightlybelowglobalpeers,ex-Chinasupplierswouldremainbelow95%utilized(92%,specifically)in2028,whichwouldnotresultinasupplyshortage(Exhibit13andExhibit14).

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP8

EXHIBIT11:BullCase:GlobalWaferSupplyvs.Demand(excludingChina)

BullCase:GlobalWaferSupplyvs.Demand

(excludingChina)

kwpm

12,000

10,000

8,000

6,000

4,000

2,000

0

SupplyDemand

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT13:BaseCase:GlobalWaferSupplyvs.Demand(excludingChina)

BaseCase:GlobalWaferSupplyvs.

kwpm

Demand(excludingChina)

10,000

8,000

6,000

4,000

2,000

0

SupplyDemand

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT12:BullCase:GlobalRawWaferUtilisation(excludingChina)

BullCase:GlobalRawWaferUtilisation

(excludingChina)

110%

105%

100%

95%

90%

85%

80%

75%

70%

Utilisation

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

EXHIBIT14:BaseCase:GlobalRawWaferUtilisation(excludingChina)

BaseCase:GlobalRawWaferUtilisation

(excludingChina)

100%

95%

90%

85%

80%

75%

70%

Utilisation

Source:Companydisclosures,SEMI,Gartner,DRAMeXchange,Bernsteinestimatesandanalysis.

WILLTHECHINESESUPPLIERSBEABLETOADDRESSTHEOVERSEAMARKET?

•Chinesesuppliersarealreadyexportingtooverseacustomers.NSIGandEswinbothderived~27%ofwafersalesfromoverseascustomersasofFY2025and1H25,respectively(Exhibit15andExhibit16).

•However,theiroverseasshipmentsarepredominantlytestwafers.Testwafersaccountforroughly23%ofNSIG'ssalesand41%ofEswin's,suggestingoverseasprimewaferpenetrationremainslimitedtoday(butnotzero,sinceNSIG’sexportratio

DavidDai,CFA+85229185704

david.dai@

20April2026

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP9

of27%ishigherthantestwaferratioof23%)(Exhibit17).

•Justbecausetheydon’tsupplynowdoesn’tmeantheyareunabletodoso.ThewaferqualityrequirementofNANDand

maturelogicisnothighandisdefinitelyaddressablebytheChinesesuppliers.SUMCOhasindicatedthatonly~20%oflogicwaferdemandisforadvancednodes.CombiningNANDandmaturelogic,weestimate~60%ofglobalwaferdemandis

technicallyaddressablebyChinesesuppliersatcurrentqualitylevels(Exhibit18).

•Attheendoftheday,rawwaferisjustacommodity,anddoesnothavechipsattachedtosendinformationbacktothe

suppliers.WedonotseeanyfundamentalreasonwhyChina’swaferscannotbesoldgloballyaslongastheymeetthequalityrequirements.

EXHIBIT15:NSIG'sWaferRevenueBreakdownbyGeography

NSIG'sWaferRevenueBreakdownbyGeography

30%27%

42%40%

53%

70%73%

58%60%

47%

20212022202320242025

ChinaNon-China

100%

80%

60%

40%

20%

0%

Source:Companydisclosures,Bernsteinanalysis.

EXHIBIT16:Eswin'sWaferRevenueBreakdownbyGeography

Eswin'sWaferRevenueBreakdownby

Geography

100%

80%

60%

40%

20%

0%

27%

73%

1H25

26%

74%

2024

26%

74%

2022

30%

70%

2021

34%

66%

2023

ChinaNon-China

Source:Companydisclosures,Bernsteinanalysis.

DavidDai,CFA+85229185704

david.dai@

20April2026

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP10

EXHIBIT17:ChineseRawWaferSuppliers'RevenueBreakdownbyPrime/TestWafers

ChineseRawWaferSuppliers'RevenueBreakdownbyPrime/TestWafers

100%

22.9%80%

16.7%60%

40%

60.4%20%

0%

NSIG

40.9%

24.6%

34.5%

Eswin

PolishedWafersEpiWafersTestWafers

NSIGasof2024;Eswinasof1H25.

Source:Companydisclosures,Bernsteinanalysis.

EXHIBIT18:ChinaWaferDemandBreakdownbyTechnology

ChinaWaferDemandBreakdown

AdvancedWafersMatureWafers

Advancedwafers:mainlyadvancedDRAMandlogic;maturewafers:mainlyNANDandmaturelogic.

Source:Companydisclosures,Bernsteinestimatesandanalysis.

38.5%

61.5%

STOCKIMPLICATIONS:PROBABLYGOODASATRADEFORNOW…BUTIT’SJUSTATRADE

•SUMCOstockup45%year-to-dateforthisreason.Globalpeers(Shin-Etsu:+40%,GlobalWafers:+24%,Siltronic:+34%)showedsametrend.

•Intotheearning,itcanbeexpectedthattheinventorydropssignificantlyforthefirsttimein6quarters,whichwillfueltheworst-behind,shortage-aheadnarrative(Exhibit19).

•SUMCOnowtradingat1.32xP/B,vs.historicalpeakis2.42x(after2019),suggestingsomeupsidetogointhenearterm(Exhibit20).Buy-sidefeedbackistheyarelookingat1.5-2xP/B.OnEV/EBITDA,thestockalreadyappearstobetradingnearpeaklevels(Exhibit21);however,ifdemandstrengthensandshortagesdrivepricehikes,EBITDAshouldalsomovehigher.

•Fundamentally,however,wearenotbullishonthesectorinthelongrungiventherisingChinesecompetition,andwewouldnotrecommendittolong-terminvestors.

•WereiterateourMarket-PerformratingonSUMCO.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP11

EXHIBIT19:Waferinventoryremainshigh,suggestingthecurrentshipmentlevelisstillabovedemand12''waferindexedinventoryandturnoverdays

indexinventory

indexdays

100

80

60

40

20

0

120

100

80

60

40

20

0

CustomerinventoryTurnoverdays

Source:SUMCO,Bernsteinanalysis.

EXHIBIT20:SUMCO:Historical1-yearforwardP/Bmultiple

2015-2026:SUMCO1-yearforwardP/B

multiple

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

P/BAverage±1SD±2SD

Source:Bloomberg,Bernsteinanalysis.

EXHIBIT21:SUMCO:Historical1-yearforwardEV/EBITDA

2018-2026:SUMCO1-yearforwardEV/EBITDAmultiple

10x9x8x7x6x5x4x3x2x1x0x

EV/EBITDAAverage

±2SDTarget

Target6.0x

±1SD

Source:Bloomberg,Bernsteinanalysis.

JAPANSEMICONDUCTORSBERNSTEINlsocIeTecENeRAlECROUP12

DISCLOSUREAPPENDIX

I.REQUIREDDISCLOSURES

Referencesto"Bernstein"orthe“Firm”inthesedisclosuresrelatetothefollowingentities:BernsteinInstitutionalServicesLLC

(April1,2024onwards),SanfordC.Bernstein&Co.,LLC(preApril1,2024),BernsteinAutonomousLLP,BSGFranceS.A.(April1,

2024onwards),SanfordC.Bernstein(HongKong)Limited盛博香港有限公司,SanfordC.Bernstein(Canada)Limited,Sanford

C.Bernstein(India)PrivateLimited(SEBIregistrationno.INH000006378),SanfordC.Bernstein(Singapore)PrivateLimited,

SanfordC.BernsteinJapanKK(サンフォード・C・バーンスタイン株式会社)andanalystsemployedbySociétéGénérale

AfricaTechnologies&ServicestoproduceBernsteinresearchunderaGlobalServicesAgreementinplacebetweenBernstein

andSociétéGénérale.

BernsteinispartofajointventurebetweenSociétéGénérale(SG)andAllianceBernstein,L.P.(AB).Unlessspecificallynotedotherwise,forpurposesofthesedisclosures,referencestoBernstein’s“affiliates”relatetobothSGandABandtheirrespectiveaffiliates.

VALUATIONMETHODOLOGY

SumcoCorp

Weseta¥1,530targetpriceusingaEV/EBITDAmultipleof6xagainstour2027EBITDAestimateof¥148.

RISKS

SumcoCorp

UpsideriskstoourSUMCOtargetprice:(1)Strongerglobaleconomyimpactingtheelectronicsdemandandhencestrongerwafersdemand(2)Fasterpaceofinventorydigestion(3)Favorableexchangeratefluctuation.Downsiderisks:(1)Weakerglobaleconomyimpactingtheelectronicsdemandandhenceweakerwafersdemand(2)Slowerpaceofinventorydigestion(3)FasterpaceofChinesecompetitorscatchingup(4)Unfavorableexchangeratefluctuation.

RATINGSDEFINITIONS,BENCHMARKSANDDISTRIBUTION

EQUITYRATINGSDEFINITIONS

Bernsteinbrand

TheBernsteinbrandratesstocksbasedonforecastsofrelativeperformanceforthenext12monthsversustheS&P500forstockslistedontheU.S.andCanadianexchanges,versustheBloombergEuropeDevelopedMarketsLargeandMidCapPriceReturnIndexEUR(EDME)forstockslistedontheEuropeanexchangesandemergingmarketsexchangesoutsideoftheAsiaPacificregion,versustheBloombergJapanLargeandMidCapPriceReturnIndexUSD(JPL)forstockslistedontheJapaneseexchanges,andversustheBloombergAsiaex-JapanLargeandMidCapPriceReturnIndex(ASIAX)forstockslistedontheAsian(ex-Japan)exchanges-unlessotherwisespecified.

TheBernsteinbrandhasthreecategoriesofratings:

•Outperform:Stockwilloutpacethemarketindexbymorethan15pp

•Market-Perform:Stockwillperforminlinewiththemarketindextowithin+/-15pp

•Underperform:Stoc