Paying people more for doing their job well? Yes, it's legal. :)

(I'm sorry if the answer comes off as flippant, but really, there's nothing particularly odd or unsavoury here. Journalists are paid to break stories that get attention or are otherwise important, and this is a perfectly valid metric for "important". Why would it be illegal?)

why wouldn't it be? they're not paying to move a particular direction, so it's not like they're pumping and dumping or shorting.

probably not. Even it is, if the cost of breaking laws is dwarfed by the revenue, i guess it's perfectly rational to do so.