The price goes down, because miners want sell their MMC as quickly as possible.
As a person who was cpu mining MMC until the gpu miner was released, I completely agree. It's depressing watching the price & profitability plummet for no good reason other than people undercutting prices for a quick sale.
In the long term, those morons are cutting everyone's, including their own golden goose's neck, and destabilizing the currency in the process with their short sightedness.
The funny thing is, you can see the same with the majority of alt cryptos ever since the news stories broke in the media. The general public saw nothing but a get rich quick scheme in their mind, and have no idea of the market consequences, & don't care about ruining the value or destroying the public confidence in the currency with their grab for the instant payoff...