Before revision: This paper considers price volatility as the reason for description of the second-degree economic variables, trades and expectations } } aggregated during certain time interval {\Delta}.
After revision: This paper considers price volatility as the reason for description of the second-degree economic variables, trades and expectations } }p2(t)and all price n-th statistical moments p(n;t) as ratio of sums of n-th degree values C(n;t) and volumes U(n;t) of market trades aggregated during certain time interval {\Delta}.