Robert was not your typical stockbroker. From all accounts he was more of a philanthropist. He even hosted a fund raiser for the American Cancer Society the night before he was murdered. At some point Robert became infected with Greed. It wasn't until the Charmed Ones intervened when Robert was begging a demon for more of what was inside the "box." Prue threw the box across the street and the moment Robert got free he ran for the box. He was killed by being hit by a bus. His soul was contained and delivered to Lukas, but was released by Leo after the demon was vanquished.