Assuming you're looking for "hot" with the goal of propogating/collecting/selling then I'd say (personal opinion)...
* Euphyllia are way too high right now. I'd put that at a SELL
* Designer shrooms (bounce, electus) seem to have kept their value, but we'll see what they're like as the Covid boom dies down. I'd put that at a HOLD/DON'T-BUY
* Zonathids will always be a reasonable investment, but for those I wouldn't buy 1-2 polyps; see if you can get deals from tank teardowns or grab mystery boxes.
* Acros may hold their value especially as some Covid-reefers get further into the hobby and have more mature tanks. So if you think you can keep and propagate it, go for that rainbow splice!
* Scolys, acanthos, and trachys seem low priced right now. You can't really frag them, but if there's another export ban, you can expect those to soar in price. As always, shop for deals, though.
* Nems seem like a good investment although I can't seem to keep them alive myself. If you can get an RBTA or Colorado Sunburst that splits every month or so, you'll have a steady stream of pieces to sell.