Dems deluded themselves the same way with Obama. You started to see the economic rebound practically the day he stepped into office. Either Obama was a wizard or we were experiencing a natural market rebound before he'd done anything.
That's not so strange , businesses are nervous before the election and will hold off investing. As soon as a reasonably sane politician is elected they will start investing again.
Yeah there is a good reason for that to be secret: it prevents buying votes because you can't prove who you votes for, if someone offers you money to vote a certain way you can always take the money and vote the other way, no way to prove how you voted.
How else would they get in your ear?