I definitely would not make this public or you will get speculators trading against you to take a slice of your $1m (by artificially inflating prices).
Or he could be lying and actually looking to sell. People who speculate on forum rumors are asking to be bitten.
this.
announcing your plans usually has no effect whatsoever. In fact, I would go as far to say that the majority of people would assume you're lying.
Depends on how trustworthy andlogical your claim is. Would you believe Benanke is lying to you when he announces QE3? You know he's got a good reason to do it, you know's got the recources and power to do so and he did it already in the past.
If No0B_user99 announces to buy 10M$ worth of bitcoin tomorrow, I would bet all my bitcoins it won't happen, but that's the other end of the spectrum.
To close the circle and come back to our case: If Mitt Romney or someone else in his name (like Donald Trump) announces to buy 1M$ worth of Bitcoin by October, I would be very tempted to believe it. Many people would be, so it would have a severe effect on price. If he really would wanna buy cheap, he wouldn't announce it though. Instead someone with good connections could announce a ruling to make bitcoin illegal or else, of believable enough, that would have a severe effect on bitcoin prices also, the other way.