No.
Do you mean legally? or morally?
Legally the offenses include things beyond what might strictly be "fraud" (see "fraud or deceit" as one example, but there are more [1]). IANAL, but failing to mention that your posts are with the hope of raising the price because you have a vested interest in that... seems like a material omission, if nothing else.
Morally (and I'd expect legally based on the text, but IANAL) what matters is what he expected to happen as a result of his posts on the message board. If he knew people would likely buy the stock in response to his posts, and he intended to take advantage of that influence to make money off those sales, that's the end of the story. Whether he sincerely believed the stock would actually rise regardless is beside the point.
> But now how do you distinguish between malice and stupidity?
I'll assume you mean good faith because stupidity isn't in the picture here. Someone who's genuinely predicting the stock market correctly isn't stupid.
Do you sincerely believe this person didn't expect his messages to raise the stock price, or that he didn't intend to take advantage of such a rise to make money off the stock sales? I sure don't.