if sam posts any regular timeline tweet (not a reply or retweet but can be a quote tweet) where he uses multiple sentences and all of them have everything correctly capitalized according to grammarly, this market resolves to "yes".

if there is no such tweet after market creation and before market close on 11:59 pm pt on june 30, this market resolves to "no".

sam does not like capital letters, as you can see here:

however, sometimes he will do it:

he's been in some hot water recently, so maybe it's time for another serious tweet?