Relative abundance comparison for the chemical equilibrium retrievals of Fig. 7 compared to the stellar (Evans-Soma et al. 2025, dashed turquoise lines) and solar (Asplund et al. 2021, dashed orange lines) values. Shown error bars are either 1 σ bounds or 3 σ upper limits. Top: ratio of refractories compared to TiO (a proxy for the degree of titanium depletion). Compared to other refractory species such as VO included in [ℛ/H], TiO has a higher condensation temperature (Lodders 2003), and hence its underabundance relative to other refractories may be indicative of some titanium being cold-trapped on the colder night-side of WASP-121b. Bottom: ratio of volatiles relative to refractories (a proxy for the ice-to-rock ratio). While our measurements are well consistent with a stellar/solar composition, we also cannot rule out the previous claims of WASP-121b harbouring a slightly rock-rich (Lothringer et al. 2021; Smith et al. 2024) or ice-rich (Pelletier et al. 2025; Evans-Soma et al. 2025) atmosphere.