If someone gives you an exact date, how would you know if they are telling the truth? Nobody knows the future. It can all collapse to $1K in a month or keep go

If someone gives you an exact date, how would you know if they are telling the truth? Nobody knows the future. It can all collapse to $1K in a month or keep going to $50K. And if someone actually knew, they would stand to make huge money and would keep their mouth shut.