This branch of coins recently blew up on Polo due to one reason.
Pump and dump.
A team was hyping those coins in typical pump and dump fashion. You can see that all three of those coins followed similar paths. The team of pumpers were buying some at first on the sly then gradually pumped and hyped, got others not part of the team to get in on it seeing the 300% growth and wanted to jump on the train. Then it was dumped at the top a bit, then repumped a bit later to get more of the FOMO "investors". Then it trickled away gradually eating up the remnants of those "investors" as they could see they had been scammed.
Just another day at the races.
RE: Research coins exploding! CMN video explains why: GridCoin, PrimeCoin, FoldingCoin, CureCoin