Composite forcasting stock price ?

[lemanioc@xxxx]

Hi,
I've noticed something and wish to have your opinion on it.

Everybody knows that very often, a stock price match its sector 
composite average.
For example, when you browse trough your biotech stocks and compare 
it to the composite of the biotech sector (^BTK), you'll notice that 
most stock match the line of the composite.

I noticed that when a stock lags behind its composite, it usually 
catch up its lag pretty fast.
For example, if the biotech composite starts to surge up after a 
downmove or a sideway pattern, if you find a stock that don't follow 
the composite, you are almost sure it will catch up its lag pretty 
soon.
Thus, one can use the average to clearly forecast what lagging stock 
will do.

Have you noticed this or conducted some research on it ?

Comments are welcome.
Thanks,
Manioc