Gap ups following price sensitive announcements are relatively...

Gap ups following price sensitive announcements are relatively rare and indicate huge interest in a stock, so it can be a pretty strong buy signal as stocks often make their biggest gains afterwards.

Have a look at DEG, classic example when it gapped up from 6 cents.

Not all price sensitive announcements result in gains to the stock. Often the best gains are made before an ann and sell on the news often holds true as good advice.

You must be new to trading to not realise this.