urbanSTL

Also to be included in the conversation, STL's large private multi-billion dollar companies: (May have left a few out) 

Enterprise Mobility
World Wide Technology
Schnuck Markets
McCarthy Holdings
Barry-Wehmiller Companies
Alberici Enterprises 
Dierbergs Markets 
Apex Oil Company

AND F1000
Belden 
Olin 
Stifel 
Peabody 
Advantage Solutions 
Energizer 
Caleres 

Too bad we can't include Bunge in there.