aegis equities research gives oil search strong bu, page-21

Would not worry about couple of insto' selling, trick is to buy when they have stopped selling.
A good trading strategy for short in and out.

Simple TA in form of Price / volume analysis should help with this.

The pattern you should look for is

Declining price - increasing volume
Stabilising price - decreasing volume
Stable (but lower) price - small volume.
Announcement AMP have reduced holding. (LOL)
BUY BUY BUY profit then SELL SELL SELL
And have a stop loss because nothing works all the time.

I stress only for stocks you know well.

If you try this with some high flyers ie. MAY or say CSL some time ago your buy order could coincide with 2nd wave of selling.
Tends to get ugly after that.

So SL as this is trading not investing strategy.