We explore the large spin spectrum in two-dimensional conformal field theories with a finite twist gap, using the modular bootstrap in the lightcone limit. By recursively solving the modular crossing equations associated to different P SL(2, Z) elements, we identify the universal contribution to the density of large spin states from the vacuum in the dual channel. Our result takes the form of a sum over P SL(2, Z) elements, 1 A priori, there could be theories without conserved currents, but with an accumulation of operators towards vanishing twist, and therefore have zero twist gap.2 These are the P SL(2, Z) images of the cusp at τ = i∞. 3 More precisely, this is a sum over the coset P SL(2, Z)/Γ ∞ where Γ ∞ is the subgroup generated by T : τ → τ + 1 that stabilizes the cusp at τ = i∞.4 In [1] this argument was credited to Tom Hartman.