How to track Pillar 3a value in finance apps?

Hi, newbie post here. I searched but couldn’t find an answer (only whether to include it or not in total NW).

When using Pillar 3a with a non-trivial strategy, it seems too much overhead to track the performance of the underlying instruments. Or if automated, still less not as useful as tracking the strategy value (which would help determine whether it’s a good strategy).

So that would mean one would track it as a virtual stock, and on the first payment, assign 1 CHF = 1 stock, then later (monthly/half-yearly/yearly), track changes in the virtual stock value to reflect the performance. How would this work then in later years, though?

  • original investment 1000 CHF, 1000 “stock”
  • after a while, stock is now 1.1 CHF (there was a 10% unrealised gain)
  • if investing another 1000 CHF, it seems one would have to use again 1.0 CHF, since the total value after the “buy” is 2100 CHF, right? and this also affects the value of the virtual stock, now at 1.05 CHF (instead of 1.10 CHF before this buy-in).
  • another increase of 10% would then mean 200*1.1=2310 CHF, for an average return of 15.5%.

I have no idea if this is a valid way to track Pillar 3 value & performance. Thoughts?

Just to provide a pointer, you may want to read about the time-weighted return method, which seems quite well explained on Wikipedia (arguably more verbose and detailed than may be appropriate for an encyclopedic summary).