MUFON 94539

Saw balloon-like object hovering I saw what I think was some kind of balloon, over central Hong Kong, China in August 2018. I was on holiday hiking and shot a very short clip with my Cannon 550D. It seemed to be hovering while gradually rotating, grey in the middle and slightly white toward each end of its roughly elliptical structure. Since I'm not a local, I didn't know who to contact about it, but I was hoping someone else saw this and can explain what it is. I wasn't aware that my camera had automatically stopped recording the video after only a few seconds, but the object remained there for several minutes after which point it started to slowly rise upward and out of sight. It was all quite slow hence my belief that it is perhaps some kind of balloon, but I admit that it did freak me out enough to send it here.
Source ID94539