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In recent years,T_dtransition metal dichalcogenides have been heavily explored for their type‐II Weyl topology, gate‐tunable superconductivity, and nontrivial edge states in the monolayer limit. Here, the Fermi surface characteristics and fundamental transport properties of similarly structured 2M‐WSe₂bulk single crystals are investigated. The measurements of the angular dependent Shubnikov–de Haas oscillations, with support from first‐principles calculations, reveal multiple three‐ and two‐dimensional Fermi pockets, one of which exhibits a nontrivial Berry's phase. In addition, it is shown that the electronic properties of 2M‐WSe₂are similar to those of orthorhombic MoTe₂and WTe₂, having a single dominant carrier type at high temperatures that evolves into coexisting electron and hole pockets with near compensation at temperatures below 100 K, suggesting the existence of a Lifshitz transition. Altogether, the observations provide evidence towards the topologically nontrivial electronic properties of 2M‐WSe₂and motivate further investigation on the topological properties of 2Mtransition metal dichalcogenides in the atomically thin limit.

Twisted transition metal dichalcogenide (TMD) bilayers have enabled the discovery of superconductivity, ferromagnetism, correlated insulators, and a series of new topological phases of matter. However, the connection between these electronic phases of matter and the underlying band structure singularities has remained largely unexplored. Here, combining magnetic circular dichroism and exciton sensing measurements, we investigate the influence of a van Hove singularity (vHS) on the correlated phases in bilayer WSe₂with twist angle between 2 and 3 degrees. By tuning the vHS across the Fermi level using electric and magnetic fields, we observe Stoner ferromagnetism below moiré lattice filling one and Chern insulators at filling one. The experimental observations are supported by the continuum model band structure calculations. Our results highlight the prospect of engineering electronic phases of matter in moiré materials by tunable van Hove singularities.