I’m thinking that this is some sort of joke article at City AM, because it’s always convention to define an acronym at first use, and they didn’t just omit it – like, it probably wasn’t just an editorial error – but put it in at the very end of the article.
It was actually defined in the last sentence of the article
“Some £448m was pulled by retail investors from environment, social and governance (ESG) funds in August”
But I scrolled the article 3 times before I spotted it, so your point stands.
I’m thinking that this is some sort of joke article at City AM, because it’s always convention to define an acronym at first use, and they didn’t just omit it – like, it probably wasn’t just an editorial error – but put it in at the very end of the article.