washington chairman u.s. securities exchange commission sec tell congressional committee tuesday believe predecessor mary jo white know 2016 cyber breach regulator corporate disclosure system exact time could know sure jay clayton formally appoint role may also say list company disclose detail information cyber breach sooner u.s. regulator work new guidelines ensure senate bank committee grill clayton tuesday 2016 hack edgar agency online corporate financial disclosure system disclose last wednesday shake confidence sec cyber defenses clayton say decide last weekend disclose breach enough information establish serious would draw agency know whether attempt cover belief sit chair white know clayton say ask whether predecessor aware hack add think know sure exact time breach clayton field several question senators recent equifax inc data breach hackers steal personal data 143 million customers credit report firm include time company disclosure although former wall street lawyer decline comment whether sec investigate stock sales make equifax executives prior disclosure say ignore issue hear schedule prior disclosure sec breach offer lawmakers company investors first opportunity hear sec chief incident clayton originally schedule discuss capital market reform first hear committee since formally appoint may pro-growth agenda largely eclipse sec breach equifax scandal wall street top regulator come fire last week disclose hackers might use information steal edgar house millions market-sensitive corporate disclosures earn release insider trade learn year fact sec breach likely lead illegal stock trade raise question sec seem sweep rug senator sherrod brown rank democratic member committee ask clayton open remark else tell information risk consequences brown ask expect company right thing agency reuters report monday federal bureau investigation u.s. secret service launch investigations breach occur october 2016 appear rout servers eastern europe breach appear one several cyber incidents document sec recent months reuters report clayton say learn 2016 hack august sec enforcement staff inspector general office launch internal probe regulator report breach department homeland security computer emergency readiness team first discover clayton say testimony add regulator plan hire cyber security experts clayton say hack possibly result defect edgar software say personally identifiable information appear put risk decline provide detail say sec still determine extent impact breach could take substantial time complete due amount data need analyze committee also quiz clayton potential breach agency regulator general cyber defenses clayton say could say 100 percent certainty edgar breach one suffer agency add plan ask congress fund tackle rise cyber threat go need money cyber security intend ask it u.s. sec chair grill senate panel cyber breach equifax