I think it is almost always done that way. Nobody wants to be accused of interfering in the market.
If something came out before the market closed and the market moved and somebody in the know made a profit even if completely innocent. Even if only a couple of hundred dollars it would be used against them.
Ohhh so that's why it's 1PM PST. Markets close exactly at that time.
Is that a good thing or a bad thing?
I think it is almost always done that way. Nobody wants to be accused of interfering in the market. If something came out before the market closed and the market moved and somebody in the know made a profit even if completely innocent. Even if only a couple of hundred dollars it would be used against them.