you have to invest at a lower price and sell at a higher one .... you need to follow the prices
If and only you have enough funds, then you can do that. And even if you invest, you can't still earn money coz you can't sell it right away. Others are scared to invest again because until now, the market doesn't show any sign of recovery of its price. As for me, just continue holding your investments. That's the best way to do as of the moment.