shareholdervalue,

I am not a market expert  but some of this reaction is famiiar:

Some bet on news which does not arrive. Many who got in low will have speculated that the AGM will bring news then withdraw, we have been around this at every meeting point and is standard reaction here.

Expectation is built into the SP before hand and when what is expected does not emerge - very normal.

Fear precipitates what is feared - very normal 

Stop losses being triggered - dagerous if there is a recovery when the dip is seen as a buying opportunity - which many do.

Computer generated trading.

Sula