The Perfect ISA Portfolio 2021 – twenty years and counting

11 min Read Published: 18 Mar 2021

Long-term 80-20 Investor members may remember that six years ago I embarked on a research endeavour to find the Perfect ISA Portfolio.

In simple terms, I was trying to work out the Perfect ISA Portfolio asset mix (or whether one even existed). Was there an asset mix that had always produced a positive return in every tax year historically? Of course that wasn't enough, as just investing in cash would have achieved this. So finding the Perfect ISA Portfolio also had to maximise the upside, far outperforming cash returns. So I created a number of rules that the Perfect ISA Portfolio had to adhere to. The rules were that:

  • There would be no constraint over which assets could be included or in what proportions they are held
  • The portfolio must have made money every tax year since the market peak back in 2000
  • and not lost money
  • It had to at least beat a FTSE 100 Index tracker over the entire time period and
  • The asset allocation had to remain constant throughout that time (with annual rebalancing to ensure this)

So, in essence, I wanted to find the perfect 'buy and forget' asset allocation.

Full article available exclusively to 80-20 Investor members.

To read the complete article, sign up for a free trial or log in below.