Hobbs initially co-presented Squawk Box Europe and also presented Europe Today and its replacement Today's Business before moving in 2003 to hosting European Closing Bell and Europe Tonight. He hosted European Closing Bell and Europe Tonight until Guy Johnson became host of both shows in March 2007. He also co-hosted Questions for the Future with Ross Westgate and towards the end of his time at CNBC Europe Simon presented an interview series called The Leaders.
He then joined CNBC in America as a stand-in presenter and, for a time, he filled in as co-host of Power Lunch before taking up co-anchoring duties in 2011 on Squawk on the Street, where he co-hosted the program's second hour. His last day on CNBC U.S. was July 29, 2016.