RT Journal Article SR Electronic A1 Mastný, Václav T1 Testing the efficiency of high-frequency foreign exchange market JF Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis YR 2015 VO 52 IS 6 SP 277 OP 286 DO 10.11118/actaun200452060277 UL https://acta.mendelu.cz/artkey/acu-200406-0023.php AB This paper deals with the efficiency of the high-frequency foreign exchange market. The objective of this paper is to investigate whether standard statistical tests give the same results for time series resampled at intervals of 15.30 and 60 min. The data used for the purpose of this paper contain major currency pairs such as EUR/USD, GBP/USD and JPY/USD. The results of statistical tests indicate that the high frequency intervals (15-minute) are not random and should not be considered independent. On the other hand, tests with lower frequency rates (30 and 60 min) indicate rising randomness of the market.