The top coins are always lower risk and the reason is they have shown promising technology/use case. Hence my core holdings are ETH, NEO, XLM, XRP and ADA.

Low MC coins have the higher risk but rewards can be ENORMOUS. My low MC coins are XSPEC and PRL.

XSPEC - After the PM Mandica let go of the bad apples in the team, XSPEC has shown to be strong team and even stronger community. They have hired core devs and are still hiring more devs and continue to push out github commits and constantly update the roadmap. Additionally the coin addresses one of the major concerns in crypto/DLT i.e. Privacy and being a POS coin makes it even more attractive.

PRL - PRL is another beaten down gem. The team is strong and constantly works on development. The prices dumped after the mainnet release but in the long term (2yr+), I think this coin will do great.