Traditionally they say buy on rumour and sell on fact...prices...

Traditionally they say buy on rumour and sell on fact...prices are pumped up in anticipation and due to mkt forces, and generally sp dips on the sell off on profit taking.
But what also has happened then in the process, is that you have created a new resistance point or sp expectation.Those who might have bought on the way up or at the high prior to selloff may also be prepared to hold indefinitely or hold for the next legup in sp.
It is very much a question on your style of investing.
Daytrader/short term/long term investor etc