I used only read one series at a time. But as the pool of completed manhwas I liked grew smaller and newer and really good looking one came out I started read, week to week series along with completed ones.
Fast forward to now, I read multiple series at a time, some week to week, some I binge until finished. Or until some character or situation gets on my nerves and I switch to a different genre ( almost like a palate cleanser ) eventually, I'll go back when I'm in the mood for that type of series again.