I’m not one of these people, having around 70% of my total wealth on IB. Call my naive, but I still have faith in IB and the Amercian justice system, feeling confident that I would be able to clarify any doubts in connection to my wealth on IB.
However, I am less confident than I was before in recommending IB to friends and family. While I think that there is a strong and reliable process for clarifying doubts, this process might be different from the Swiss and European thinking. This might make it seem more complicated to get your rights enforced. I therefore only recommend IB to friends and family that have the mindset to deal with such issues and processes.
I only started splitting (you can do that with a simple position transfer and keep buying at IB), after reaching (multiple) 7 digits at IB. At that point the cost of the 90 CHF/year at Postfinance for diversification seemed pretty cheap.
With several 7 digits and safely in FIRE territory, one might even think about only using e.g. Finpension or VIAC for their automated portfolio management and draw-down plan which is 100% set and forget and fully under Swiss jurisdiction.
I don’t keep any sort of asset in one place.
Multiple bank accounts and brokerages
Somehow I had 1974 in my mind. Still a substantial history.
I recommend reading this conversation: https://forum.mustachianpost.com/t/the-end-of-ibkr-vt-a-cheaper-safer-less-us-dependent-alternative/
In my opinion, there is no upside compared to relying on UCITS funds held at European providers, only considerable downsides. I would advise against moving your assets to an American provider.
then put 50% in IBKR and 50% in Saxo.
Personally I buy individual stocks, that is so much better at IBKR.