Amway Chairman Steve Van Andel and siblings David Van Andel, Barb Van Andel-Gaby and Nan Van Andel own half of Alticor Inc., Amway's Ada-based parent. The stake — which they inherited in equal shares after their father, Jay Van Andel, died in 2004 — is valued at $4 billion, according to the Bloomberg Billionaires Index. Richard DeVos, 88, owns the other half of Alticor. He has a $4.5 billion fortune, according to the Bloomberg ranking.