No I don't think so that these speculations affect the price of BTC. Suppose is it so then why not to increase as well? Some people are also speculating positive as well. I think price goes down suddenly whenever there is a change in rules of trading in any country. Some people who believe rules strongly, they use to stop trading after getting bad news about BTC or change in trading rules. Although it is ban in many countries but you can see that people of that country are trading. Have a look a localbitcoins then you will get an idea that how many people from how many countries are dealing with btc trading.