Let Pt be the observed market price of an asset, which is related to the fundamental value of the asset via Eq. (5.9). Assume that ? = - -1 forms a Gaussian white noise series with mean zero and variance 1.0. Suppose that the bid-ask spread is two ticks.
What is the lag-1 autocorrelation of the price change series ?Pt = Pt - Pt-1 when the tick size is $1/8?
What is the lag-1 autocorrelation of the price change when the tick size is $1/16?