That choice is not wrong, because Bitcoin and Ethereum are the best coins today as Cryptocurrency coins. But why do we have to sell all the coins we have, if only to buy two coins, isn't the more types of coins we invest in, the greater our chance of making profits. If I personally keep investing other coins, and not only Bitcoin and Ethereum. Coins such as BCH, LTC, ADA, NEO and many other top-ranking coins are also worth investing.