These days20 Jul 2016 15:39
I don't think the mm's or brokers are a ny different from any other company. There's not much money around in their world, therefore they can't hold stocks, need to keep themselves in cash etc... So they mark the prices down in the hope of making on any small gains.
When the price starts to go up they buy on spec themselves, mark the prices really high and the sell their shares into the market.. Then drop the prices, creating spiking rises all the time.
I don't think private investors have very much to do with prices changes anymore, news certainly doesn't seem to matter much on any stock.
All my own opinion for what it's worth.