Stellar-to-halo mass relation at z = 6 in OBELISK (black dots), compared to the model of Behroozi et al. (2019, in blue), and to the NEW-HORIZON simulation Dubois et al. (2021, in red) at the same redshift but for an average environment. The dashed and dotted lines indicate the 1:1 relation and the universal baryon fraction, respectively. For haloes with M_vir > 10^9.5 M_⊙, the stellar mass in OBELISK exceeds that of NEW-HORIZON, highlighting the role of the overdensity.