TY JOUR TI MATHEMATICAL MODELING OF ABNORMAL CRYPTOCURRENCY RETURNS UNDER THE INFLUENCE OF INFORMATION EVENTS KW cryptocurrency market dynamics KW market capitalization KW daily cryptocurrency returns KW cryptocurrency news sentiment KW informational event effect KW market manipulation KW cryptocurrency infovolatility KW investor behavior KW trading volume JO MOSCOW ECONOMIC JOURNAL AU Sidorov, A.A. AU Burceva, T.A. AU Darda, E.S. AU Paraskevopulo, O.R. PY 2026 IS 11 PB Electronic science