system
A chat on subreddit /r/wallstreetbets
human
China, The Fed, US citizens, other countries with soverign funds that buy T-bills and such.  Being the most credit worthy nation on Earth means Congress can flick the pen on bills and print dollars but it's still reckless the last decades.  

The one that bothers me the most is the Fed.  It's like a meta ownership of sorts, they simply buy bonds (QE) to aid US economically but its our central bank...seems a superficial mechanism which it probably ultimately is.
gpt
It’s the same trick FTX did.