Variability of the 2019 Balmer lines of EX Lup. Top row: Hα(left), Hβ(middle), and Hγ(right) residual lines profiles. Each colour represents a different observation. Bottom row: Hα(left), Hβ(middle), and Hγ(right) residual line auto-correlation matrices. The colour-code scales the correlation coefficient. Light yellow represents a strong correlation, and dark purple shows a strong anti-correlation. The strong anti-correlation around +350 km s⁻¹ in the Hβ and Hγ matrices is probably an artefact because it is located in a part of the continuum that varies very little.