ㄴ가 일어나다

something happens; get up

일어나다 means both 'happen' and 'get up out of bed', and both are here. Most lines are 뭔가 일어나다 — 미국 시장에 무엇인가 일어나고 있다, 'something is happening in the US market' — where 뭔가 is 'something'. One is the getting-up sense: 뭔가 일어나서 조금이라도 움직이고. And after a number, -인가 just makes it approximate: 8시 10분인가 일어났나?, 'I woke around 8:10, I think'.