1 INTRODUCTION
2 OBSERVATIONS
2.1 WASP-69b
2.2 HD 189733 b
2.3 WASP-21b
2.4 WASP-49b
2.5 WASP-79b
2.6 WASP-76b
2.7 MASCARA-2b/KELT-20b
2.8 WASP-121b
2.9 WASP-189b
2.10 KELT-9b
3 TRANSMISSION SPECTRA
4 RESULTS: A HOMOGENEOUS SODIUM SURVEY
5 SODIUM TRENDS IN GAS GIANT ATMOSPHERES
6 SUMMARY AND CONCLUSION