There's nothing unusual in NYSE reacting to changes in hot shot CEOs status, including health.

Steve Jobs is a perfect example. Apple stock reacted to his illness and reacted to his recovery. He never fully disclosed his condition and there was plenty of speculation on its exact nature.

Speculation is fine, starting rumors is not. If there was a rumor of his death and in the few hours that would take to officially deny it there was a 6% drop in Apple stock and some companies made billions of dollars on it, you can be sure the authorities would investigate it.

In Thailand they were playing on the lack of trust in the official information and possibility of a cover up of such an important announcement. "If the King died, the govt would keep it under the cover for a while, sell you stocks while you can" logic.

In some way it worked, but the folks on SET realized where the weakness lies and, as they haven't been caught hiding important info, they look a bit more reliable now and pulling a trick like this again would probably not work. Thailand would look even more professional if they found who was behind all this.

I understand how those obsessed with monarchy would turn it into another bashing opportunity, but the case has nothing to do with it, it was stock manipulation, pure and simple.