My version of MetaStock Professional is 9.1, and my question concerns MetaStock's indicator, MS2005 - Smoothed Adaptive Stoch Osc. The formula of the slightly (cosmetically) modified version of the indicator that I use is as follows: n:=Input("Std Dev lookback period",1,50,8); x:=Input("%K smoothing ma",1,50,5); lenmax:=28; lenmin:=7; v1:=Stdev(C,n); v2:=HHV(v1,n); v3:=LLV(v1,n); v4:=((v1-v3)/(v2-v3)); currlen:=(Int(lenmin+(lenmax-lenmin)*(1-v4))); hh:=HHV(H,LastValue(currlen)); ll:=LLV(L,LastValue(currlen)); Check:=If((hh-ll)=0,0.0001,(hh-ll)); RawStochK:=((C-ll)/Check)*100; Mov(RawStochK,x,E)-50; 40; -40 What I find strange is that frequently (not always), when updating in RT, past screen elements of the data array of the MS2005 - Smoothed Adaptive Stochastic Oscillator collectively change instead of just the last period, as is the case with all other indicators in my template. The changes aren't drastic but disturbing when I would like to think that those elements occurring in the past are now set. I enjoy the forum and appreciate any explanations you might have.

The LastValue() function utilizes hindsight when plotting previous values. As the last bar's value changes, so do all previous bar's values. jose '-)

What Jose says makes sense. I'm left, though, with the question of the reasoning of the MetaStock programmers. Was the lastvalue issue recognized as an acceptable way for the indicator to perform, or perhaps might the result have been overlooked? Maybe there is an update to the indicator. I like the indicator and its use of Stdev() and will probably retain it regardless, although not without something of a nagging doubt. And thanks Jose for your response.

This post may be of some interest here. jose '-)