so shkreli and roaring kitty were both mods on /r/wallstreetbets. both of them were, at the time, licensed finance pros. shkreli of course took his L but roaring kitty used to post videos on youtube like a few times a week talking his book.
but if you remember the $GME short squeeze, that was orchestrated by roaring kitty on /r/wsb. that was his baby. he had been talking up that position for like over a year iirc. and he basically crowdsourced the squeeze, which is why he ended up in front of congress.