Hi HtLiao, thanks for the welcome :D
Ohhh early 2016?? well you must have done well ! Holding the major coins sounds like a great strategy to me and why change what works.
The bulk of my portfolio is Eth, and I'll always have at least 50% minimum (more like 70%) of my portfolio in either Eth or BTC...they are just going to be solid growers in my opinion.
There are so many other coins out there though, worth having an investigate - but consider them speculative / high risk relative to your bread n butter solid higher market cap premiums. Some of the alt coin investments for me are more to support the ideas, teams and products I like, although I do expect pretty much the whole market to go up over time as the crypto market cap grows.