economy
FBI seized phone of Guggenheim executive in probe of Mark Walter’s business empire
US scrutiny of billionaire’s sprawling finance holdings reached beyond insurers into securities and asset management giant

TL;DR
- The FBI seized the phone of a Guggenheim executive.
- The seizure is part of a federal investigation into billionaire Mark Walter's business empire.
- The probe has expanded to include securities and asset management, beyond previous scrutiny of insurers.
- The investigation signifies increased US scrutiny of Walter's sprawling financial holdings.