"Sig" buys short dated treasuries instead of holding cash.
If I get it right, "Sig" buys short dated treasuries in US dollars for totally another purpose, he's not bothered by negative interest rates.
Short term treasuries in EUR offer negative yield too, so that's not an answer.
I've never found an easy turnaround, every solution has risks potentially greater the 1.1%/y.
As far as I know, only solution is using multiple brokers (not 100% satisfactory, I know....).
Thanks Tonyf, this is a solution that I had evaluated, but in my case it is not applicable because I should have several dozen sub-accounts with all the complications that would result for their management.
Just to let me know, has IB confirmed the limit of 100k EUR is evaluated at the sub account level?