Typically a bypass trust is worded so that at the time of death assets equivalent to the current legal estate tax exemption divert to the trust, generally benefiting the children.
The market was re-created as London's Eurobond market, which now accounts for a large slice of City of London business (and is currently being fiercely defended in the City against proposals by the European Commission for a withholding tax that would very likely divert the business elsewhere).