The trend for the last bullrun appeared to be coins that focused on either privacy or scalability.
really. why don't i remember this then?
i remember that there was some hype only for a short amount of time about privacy coins but that didn't really go anywhere. we had the ZCash and OnionCoin for a while but it didn't last.
then ever since the spam attack against bitcoin began in 2017 a lot of altcoins started advertising themselves as "solving bitcoin scaling problems" but ever since ethereum failed miserably with cryptokitties and its fees shot through the roof into 2 digits dollars people gave up on that hype too.
The last bull season actually affected the whole market deeply. The price for all coins from A to Z rose considerably. Obviously almost every type of project had risen. I think the bull will be more effective and the price of all altcoins will increase. But If I choose one, I may choose AI project. I think they are mirroring the future for us.