Bitcoin USD value is going up and as a result ALT/BTC pairs are lowering in price. This is all natural. I mean, just look at coinmarketcap? Coins like Ethereum are up 15% even despite this.
The goal of most of investors are BTC and USD, they only invest in altcoin to grow their fund so they can earn more bitcoin or usd. In my opinion altcoins which is safe for long term investment is only ETH, BCH, Litecoin, XMR, Golem, XCPO and other altcoin which has huge market cap. People love to trade altcoin in good exchanges site like cryptopia or other exchanges site only for gain bitcoin.