The GigaTracker is a hybrid silicon pixel detector built for the \NA62\ experiment aiming at measuring the branching fraction of the ultra-rare kaon decay K + → π + ν ν ¯ at the \CERN\ SPS. The detector has to track particles in a beam with a flux reaching 1.3 MHz/mm2 and provide single-hit timing with 200 ps \RMS\ resolution for a total material budget of less than 0.5% \X0\ per station. The tracker comprises three 60.8 mm×27 mm stations installed in vacuum ( ∼ 10 − 6 mbar ) and cooled with liquid \C6F14\ circulating through micro-channels etched inside a few hundred micron thick silicon plates. Each station is composed of a 200 μm thick silicon sensor read out by 2×5 custom 100 μm thick ASICs, called TDCPix. Each chip contains 40×45 asynchronous pixels, 300 μm×300 μm each and is instrumented with 100 ps bin time-to-digital converters. In order to cope with the high rate, the \TDCPix\ is equipped with four 3.2 Gb/s serialisers sending out the data. We will describe the detector and the results from the 2014 and 2015 \NA62\ runs.