I agree to a degree with a above opinions, that big coins are safe etc... However, well selected small coins can have a much bigger potential to grow! You always see many small coins grow a lot faster than eg. BTC in bull markets, almost indifferently to their fundamentals. But of course one should pick coins for longer term investment that have good fundamentals too. One of my smallest market-cap coin is XSPEC, in that I see a promise of sustainable price increase. Check it out at https://spectreproject.io. Now that it has a new and much bigger dev team with solid funding, I placed quite a chunk of my otherwise colourful portfolio in this coin.