BTC continues to dominate. As alt currencies approach historic lows, expect resistance to grow. Notice that the decline of alt coins is quite sharp:
(ETH trading shown above). During sharp declines there is usually a rapid bounce back before the pattern normalizes. As seen with Ethereum there could be short term trading opportunities. If you spot early a sharp change in trading, where Ethereum suddenly experiences an increase and trading volume is high, make a short term trade for ETH.