Roll’s estimator (Roll, 1984) of the effective bid–ask spread is , with the first autocovariance of trade-price changes: under pure bounce around an efficient price, trades are at mid with independent signs, and .
Quantitative Finance · Glosario
Quantitative Finance · Glosario
Roll’s estimator (Roll, 1984) of the effective bid–ask spread is , with the first autocovariance of trade-price changes: under pure bounce around an efficient price, trades are at mid with independent signs, and .