There are plenty things going on at the moment and I think NEM was way undervalued and still is, so marketcap is more than fair imho. Having said that, this jump in USD price is definitely driven by BTC, and one wonders (apart from halving) what is the intrinsic reason for BTC to double the price in a month apart from speculation. The only answer I can find is nothing
Inflation and/or devaluation of fiat currencies: USD, EUR, YEN, YUAN, ....
Negative interest rates in Japan and on german bonds.
Possible Brexit.
...