If we take a look at markets on coinmarketcap, there is a weird amount of trading to USDT. It's funny that the first two exchanges are marked as 'volume excluded', which I guess means that the reported volume is incorrect. I am no expert, but this looks like a price manipulation to me. Let's take a look at the news. Some just state that the is a bullish trend without providing explanation. Forbes says it's because Bitmain files for IPO (xenomorphe1 mentioned this reason above as well) and Bitcoin cash has something to do with Bitmain (if though there's no direct connection between these two). Now is a good time for long-term bch investment, but perhaps the price will get lower again and it's reasonable to wait.