>In this particular case, the trader in question would have been financially ruined if his spoofed orders had been executed, so it's pretty clear he didn't intend for them to be.

Are you sure? If he bought the stocks at the heightened price he could just resell them right away. I'd have expected it would take a much more permanent shift to ruin him.

Or if I put it another way: It seems to me that there is a solid method for making money that's 95% the same as spoofing and 5% actually being happy when your "fake" orders execute. So the intent is still to manipulate the market but only through truthful orders. Then you can no longer look at this pattern of behavior and say that it's overwhelmingly likely to be spoofing. Now what do you do? Do any laws stop this?