As shown in the comparison below, it's worth paying attention to the accelerated bloodshed in the altcoin market at the moment that has reached 86% this year so far. Compared to the 82% correction in the altcoin market that lasted for 9 months in 2014, the charts suggest the altcoin market could now be oversold as Bitcoin corrects further.
There are numerous arguments to suggest the Bitcoin and Altcoin corrections will sink the cryptocurrency market further, due to Bitcoin's low dominance in 2018 as well as the overvalued ICO and altcoin market, as opposed to BTC's near monopoly in 2014.
This is a legitimate argument for why altcoins will continue correcting aggressively, as Bitcoin continues a correction towards $4k to complete an 80% reduction in value (currently this is at 70%). This would be similar to the correction of 2014, in order for the Crypto Market to lose over 80% of it's 2018 value (currently the market has lost 78%)
It's however worth noting the oversold Altcoin market began a strong recovery on August 19th 2014 after 9 months of correction, whereas Bitcoin and therefore the overall Crypto Market took until January 2015, totaling 14 months until a low was reached, an additional 5 months.
In contrast, the altcoin market started it's 4 month bull-run initially gaining over 250% from August 19th 2014 to December 23rd 2014, while the pack leader fell another 30% from $475 to $334 before finding support at $200 in January 2015 to complete it's 80% correction.
The altcoin market notably followed with a 68% correction from the 2014 highs until May 2015, while Bitcoin traded predominantly sideways, gaining more dominance. However, the altcoin bears notably failed to make a lower low that year.