how can i tell if a decline in an uptrend is just a pullback or something more 
the first place to look is at the fundamental story behind the uptrend has fresh negative news hit the particular security and precipitated the pullback or is the pullback part of an overall general market decline e g wall street had a bad day you can also monitor key technical support levels to see if they hold in case they fail you might be looking at a more significant correction or even a reversal 