Back in the fifty, Nicolas Darvas was a wall-street personality. He used his boxes method, for automatic entry and stoploss, and made a fortune ..

Darvas identified the high of a box file once that action had not reached a high after three consecutive days and ditto for the lower limit, no new low after 3 consecutive days. Other criteria were also considered to constitute an input point.

But each overflow of the high limit once he was in position, he made a new entry with new add orders. The stop was always placed on the lower limit of the box

Warning from “hk-lisse” on his blog:

1. Indicator introduce a bullish bias because to form a new box, we always start to draw it from the top
2. The code make use of future price that are not known at present time

   rem from hk_lisse blog
   k=48
   once tth=undefined
   once ttl=undefined
   n=(k*2)-4
   p=(n/2)-1
   h1=dpo[n](high)
   moyh=high-h1
   hi=(moyh-moyh[1]+(high[p])/n)*n
   hi=(round(hi*100))/100
   l1=dpo[n](low)
   moyl=low-l1
   lo=(moyl-moyl[1]+(low[p])/n)*n
   lo=(round(lo*100))/100
   low1=(round(low*100))/100
   high1=(round(high*100))/100
   
   if barindex > 100 then
    if box=1 and (high1>tth or low1<ttl) then
     box=0
     flag=0
    endif
    if box=0 and flag=0 and high1>=hi[46] and high1>=hi[45] and high1>=hi[44] then
     th=high1
     flag=1
    endif
    if box=0 and flag=1 then
     for zz=0 to 44
      if  hi[47-zz-1]>th or hi[47-zz-2]>th or hi[47-zz-3]>th then
       flag=0
     break
     endif
     if lo[47-zz]<lo[47-zz-1] and lo[47-zz]<lo[47-zz-2] and lo[47-zz]<lo[47-zz-3] then
      box=1
      tth=th
      ttl=lo[47-zz]
     break
     endif
    next
   endif
   else
     tth=undefined
     ttl=undefined
    endif
     if box=1 then
      ba=ttl
     else
      ba=tth
     endif
     if box=1 then
      col=1
     else
      col=-1
     endif
   
   return ba coloured by col , tth coloured by col,ttl coloured by col

   For drawing purpose : add a fill color between the 1 and 2 return values.
   Set the first one in points, the second  and third one in large points.