RT Journal Article T1 Early prediction of Ibex 35 movements A1 Miranda García, Isabel Marta A1 Segovia-Vargas, M.J. A1 Mori, U A1 Lozano, J. A. K1 Artificial intelligence K1 High-frequency data K1 Intraday pattern K1 Price discovery K1 Stock price prediction K1 Trading hours AB In this paper, we examine the early predictability of the market's directional movement using intraday high-frequency data (695,764 observations) from an stock index (Ibex 35 Index) to provide, either private or institutional investors, an early warning system based on an “early indicator” of the financial market fluctuations with an optimal combination of the two more relevant variables for this strategy, accuracy, and earliness. A novel supervised machine learning early classification technique (Artificial Intelligence) has been applied, for thefirst time, to the high-frequency time series of both price and certain technical indicators. The results obtained allow us to assert that the intraday movement of the Ibex 35 can be predicted with acceptable levels of accuracy 24 min after the start of the session and to establish certain informative intraday hourly patterns. Consequently, different indicators of precision and earliness in the session are generated, obtaining that, after a certain point in the session, no gains in precision are generated. PB John Wiley & Sons, Ltd SN 1099-131X YR 2022 FD 2022-11-17 LK https://hdl.handle.net/10433/22760 UL https://hdl.handle.net/10433/22760 LA en NO Journal of Forecasting, 42(5), 1150–1166. NO Departamento de Economía Financiera y Contabilidad. Universidad Pablo de Olavide DS RIO RD May 8, 2026