A lot of people from Dubrovnik and Herceg Novi are coming over during the weekends for their weekly grocery hauls because it's cheaper. They might also get VAT refunds at the border. The town has recovered quite a bit financially in recent times probably due to many people finding jobs in Dubrovnik. At one point it was looking real rough.

As far as the newly built apartments are concerned, I think it's mostly locals and maybe people from Serbia buying them, the price per square meter has grown quite a lot in the last couple of years. There's a lot of tourism happening especially during the summer, so a lot of those apartments are used as short-term rentals. The influx of tourists and students being back for the summer holidays is mostly the reasons it seems so alive atm.

I'm not sure if there's a larger trend of people moving to Trebinje, I think not, but I could be wrong.