I noticed that too. It's as though all the bots got shut off and the big boys had a huddle. But it wasn't just the miners, it was every stock. How did this suspension of trading happen, with not one shred of news to accompany it? "The market" is a f ing joke!!
Yes, the markets are manipulated but no, the YAHOO chart you post is only an indication of the breakdown on YAHOO's market data today. Take a look at the same overlay over on stockchartsDOTcom and you'll see there is no flat lining. The flat sloping lines you see represent a period of no data, rather than no trades.