Who can say?

Who can say?

No one really knows (to truth about or answer to something). A: "What does the future hold, now that you've left the music industry?" B: "Who can say, really? I've always been interested in writing a novel, so I may pursue that." A: "Why on earth have they decided to go this route with the new software?" B: "Who can say what convoluted analytics they employ to come up with their new designs?"
See also: can, who
Farlex Dictionary of Idioms.

who can ˈsay (...)?

(spoken) used to say that nobody knows the answer to a question: Who can say what will happen next year?
See also: can, who
Farlex Partner Idioms Dictionary
See also:
  • Who's to say?
  • Who can tell?
  • somewhere to hang hat
  • somewhere/some place to hang (up) (one's) hat
  • into
  • be into
  • be into (someone or something)
  • be into something
  • at the back of beyond
  • coulda