The bid-offer spread as a function of daily trading volume is given by :p(q) = a + b*exp(cq)
where q = daily trading volume
a = 0.08
b= 0.10
c = 0.05
A trader wants to unwind a position of 50 million units over a period of 3 days. The daily volatility of price change of the position is $0.50. Determine the optimal liquidation quantity for each day if the trader wants to minimize liquidation and market risk costs with a confidence level of 95% (λ = 1.64).