Internally a corporation is a command economy, externally it isn’t of course.
Other command economy examples - gov’t, the USSR, the US during wartime, Russia right now, etc.
Aka when someone in a position of authority says ‘money gets spent here and this way’, regardless of any natural market tendencies (and sometimes with little regard to solvency or pesky things like quality of life).
Obviously the caveat here is that the "market tendencies" aren't defined democractically. It's very much "voting with your dollar" where the voting itself is limited to what options the market provides and the dollar is limited to how much money each market participant has. In that sense monopolization is very much a natural market tendency although most people in favor of "letting the market decide" over government control/intervention would argue that monopolization is bad and actively harmful to a free market.
Command economies like corporations?