As SCIII mentioned my dates are not "evenly spaced in time". True, at random times I check the value of my investments and again as SGIII says "Purists would say that is misleading". But it works for me.
I had hoped to be able to squeeze more data points along the "Dates/x-axis" so my chart stays on one screen. Currently.. when my chart is "full" I just duplicate it, place the copy lower down on my page and re-adjust the range of the data.
Thanks again for all the advice/help, Apple numbers is new to me and this whole exercise gave me valuable insights into the difference between Numbers and Excel
Cheers