Cryptocurrency market capitalization is believed to be skyrocketing in 2018. There are many factors that support the growth of the cryptocurrency market, such as increased legality certainty over cryptocurrency, the maturing technology and cryptocurrency market, and the implementation of banking data transparency worldwide. And if compared to other investment market, cryptocurrency market is still very small. And when talking about profit, cryptocurrency is champion in the year 2017.
While the cryptocurrency market will continue to grow, Bitcoin's dominance is expected to continue to diminish. In 2016 Bitcoin's market share is still about 85 percent. In 2017 Bitcoin dominance fell to the level of 40 percent. This means more and more altcoin growing. In the year 2017 some altcoins that experienced tremendous growth include: Ethereum, Litecoin, Ripple, and Dash. In 2018 it is estimated that Bitcoin's dominance will be lower. It is not impossible that Bitcoin's throne as a cryptocurrency with the largest market capitalization will be captured by Ethereum or Ripple. One indication of the faded charm of Bitcoin is the loss of support from Bitcoin.com site managers who are disillusioned with the development of Bitcoin and have swapped all of its Bitcoin into Bitcoin Cash.
The only reason to your question is that people afraid to loose their money they know that investing in crypto is full of risk so if they invest in wrong currency then they will loose their capital. People afraid to invest in any type of business not only in cryptocurrencies, because they don't want to loose their money they only want to get high profit always.
There are many reasons why the market cap will increase in the second half on the year and regulations of ETFs will play a large role. Now would be the best time to get in but people have too much fear right now.
That is why a lot more people invest during a bull run, the majority is seemingly making money while in the bear market the majority feel they are loosing money. In reality that opposite is true. The risk to loose money in a bull market is actually higher as you buy projects that are overhyped and overpriced while in a bear market everything is on discount. But most people think short term and act impulsively instead of looking at the long term and make decisions based on research instead emotions.