Out of curiosity, is there any reason you did not mention Peercoin?

It was launched in 2012 as ppcoin with a trading symbol PPC

It was renamed Peercoin and known today that way.

That code was the invention of Proof-of-Stake on the blockchain that many of the coins you mentioned have forked their source from (which is Peercoin)

Peercoin is alive and well. It's currently 0.5.4 but soon to be released 0.6

The chain is stable. There's lots of value stored in the chain, and it is very popular with most major exchanges.

It is weird to talk about PoS coins and not mention Peercoin.

For a reference, in Dec 2016 Peercoin was trading at 0.23 on Dec 31st.

Today, it is trading at $1.69

In less than a year, the value has jumped huge. Give it another year, it will probably jump huge again.

Is it simply because you are not familiar with Peercoin, or ?