You can always buy some when the market is down, so why not invest now.
That is basically the ideal thing to be doing right now, because I believe anyone who is busy selling right now is definitely not doing themselves the best when it comes to making the right market decisions. Like Tom said, you cannot be going bearish when the market is already in a bear phase and a terrible one, which is the time you should be going bullish and be accumulating more.
People tend to wrestle with the trend and then panic when they are being pushed out as a result of their emotions. If you know the potential of what you are holding, you will always know how to make the right decisions, focusing on the long term. Basic principle those who have been holding for years now have been using.
Any smart person will know that when it comes to taking advantage of the market and be buying, that is when everyone is busy panicking and selling. Sell when people are greedy, and buy when people are scared, it is just plain simple. Trading bitcoin at the moment though requires a good level of understanding, but for someone who is looking to investment, just keep picking gradually because as time goes on, you will realize that you have more to gain than lose.