Abundance metric for TiO as a function of C/O and O/H ratios. For C/O ≥ 0.9, the lower temperatures at lower pressures compress the upper atmosphere. This compression, when normalised by H_eq (which is unaffected by C/O) results in the rapid shrink in the metric. The circles and thin diamonds are our physical and chemical models which are compared with observations of hot Jupiters HD 209458b (star; Désert et al. 2008), WASP-74b (square; Mancini et al. 2019), WASP-19b (diamond; Huitson et al. 2013; Sedaghati et al. 2017), WASP-121b(hexagon; Evans et al. 2016), and WASP-76b (octagon; Fu et al. 2020).