Question

A government where the power is shared among a small group of wealthy individuals

Answer 1

I got Oligarchy. you can look it up just to double check though.

Answer 2

Probably the answer you seek is OLIGARCHY

Further explanation:

When you say "small group," then oligarchy is likely the best description. Oligarchy means "rule by a few." Based on the description, though, "a small group of wealthy citizens," another term that could have been used would be plutocracy, which means rule by the rich.