Firstly made a change on when to well...
Don't make it sound delusional.... exchanges have been hitted with a lot of hacks , seeing an accusations of stollen funds while researching doesn't mean that exchange is completely a red tag although some are obvious not to mention.. maybe the word reputable was too much on your side...
Hacks are inevitable, that's why i mentioned top exchanges (top 20 by volume) listed on cmc or coingecko should be the people's first choice, most exchanges on this list with hack issue can still operates and refunded their users, unlike those small ones.
Researching always give you hint and knowledge on what are good and bad, accusations thread/post of "stolen funds" doesn't mean anything if it was resolved at the end which most reputable exchanges do, unless the exchange has a reputation of selective scamming, locking funds, worst cs, you name it, that's why the word "DYOR" has was made.