The production of modern composite materials based on bulk metallic glasses requires knowledge of their primary crystallization processes during heating (BMG). Here, we investigate the structure and crystallization kinetics of a promising modern BMG/B2 nano-composites, a fast-hardened glass-forming alloy Cu50Zr42.5Ti7.5. The complex four-step crystallization of the glass alloy at different heating rates was revealed by differential scanning calorimetry. The process of a crystallization was successfully fully described by a multiverse nonlinear kinetic model, and the kinetic parameters were determined with high accuracy. The best way to describe the four-step crystallization of a glass alloy is the two-branch parallel reaction. The first branch is described by three consecutive n-order autocatalytic reactions. The second branch obeys the Avrami-Erofeev model. The high thermal stability of the amorphous state is evidenced by the average full process crystallization activation energy Ea = 425 kJ mol−1. Analysis of the obtained results and their comparison with available literature data allow us to conclude that the crystallization process in glassy Cu50Zr42.5Ti7.5 alloy (and probably other similar ternary alloys based on binary Cu50Zr50 system) is strongly affected by the structure of initial sample as well as by thermal conditions. The presence of nano-sized inclusion of metastable phases (for example, B2 one) can change the sequence of reaction as well as the structure of phases forming at each stage. © Akadémiai Kiadó, Budapest, Hungary 2024.