It is always good to buy both coins because already their developments teams are very active in the market. But the prices have decreased a lot in the market and now it is the right choice to buy as many coins as possible in the market.
This means that there are ups and downs in the price of ETH just like that of Bitcoin. It is okay to have a down market for sometimes. It actually helped eliminate the impotent coins from the market that had been creating so much ambiguity. Now, ETH and the rest of the coins are cheap and it is the right time to invest in ETH or LTC because of a reduction in the cost of investment. This will in turn rise the marginal profit that could be earned in these given coins.