The entire movement start as a consequence of approval by Japan of Bitcoin as same legal value as traditional currencies. We are talking about the world's third-largest economy with a currency (the yen) which is the second in the world for liquidity and volumes of trade in global markets.
So, I still thinking it's speculation but if you want an example of manipulation I may quote the Swiss National Bank (SNB) which in January 2015 surprised the world when the SNB’s floor of 1.20 Swiss francs per euro was dissolved without warning during the trading day, burning thousands of accounts and taking down even some brokers.