The hardest time to invest is in a bear market. You end up purchasing little amount of tokens for more ETH or BTC. But it's also a good time for projects to collect good sums of money during their crowdfunding, as ETH or BTC goes up, so does the value of the funds raised.
The question now is, will you invest in ICOs, or stick with investing in market dips (buy low, hodl and wait to go up and sell), or simply trade in bear markets?
You have to be very selective in order to choose a profitable one. The bear market delayed many interesting ICOs. Sooner or later, the bear market will come to an end, so a new kind of ICOs might shine in the future.