It will be very difficult to dump the market further(it is possible, but it will be very difficult and dangerous), because the miners are already working at a loss on some coins, like ethereum. Bitcoin almost fell to mining cost price, so, i think, it worth to start to buy now.
Bitcoin price already gone to the bottom since Dec 2018, it was about $3400 per coin.
now bitcoin value has increasing slowly, but i think we still can buy it now and make profit later because the price is not too high.