I think one should first decide their asset allocation for the full portfolio (3a + taxable). Once it’s clear, then the math needs to be done
- assets in 3a won’t have income tax but will have withdrawal tax. Depending on cantons, it can be quite an impact.
- assets out of 3a will have income tax but not have withdrawal tax , but will have wealth tax. So in this segment marginal tax rates and wealth tax rate play a role.
The volatility of the full portfolio should be taken into account (taxable + 3a). In my view, it doesn’t really matter if the portion inside 3a is less or more volatile.
Once I tried to do similar math for bonds and stocks , in and out of 3a, my conclusion for my own situation was that if I want bonds, I should keep in 3a first and only put them in taxable once I have exhausted the 3a. Post
P.S -: Ben Felix made a video about real estate investing sometime back. Might be interesting for you.