Does anyone whether this will be public information immediately? I mean, it really is quite simple to take advantage of such knowledge in advance in the Bitcoin market and I doubt there exist any laws against it.
If/When the ETF is approved within 2 hours of approval it will be on the major media sites.
After that it will be 2-6 weeks before its released on the Nasdaq for purchasing, this will give people time to anticipate it. Some already are ready for it.

Okay, so an approval cannot be kept confidential (or tentatively approved) for a week or something before it's made transparent to the world?