Hello,I read a paper form Almgren and Chriss on optimal exectution.They show that in their model, if you want to liquidate N stocks in a certain time horizon, the solution which minimizes expected market impact cost is when you liquidate an equal number of stocks at each time step. That is you liquidate N/nt stocks at each time step, where nt is the number of time steps until the time horizon.Is there a qualitative explanation for that, without any calculations? Why when you liquidate your position linearly in time, does it give minimum expected transaction costs?Thanks,Sothiro