What's happened is since the last rise a lot more trade volume has entered the market, so it will be a lot more difficult mess with the price short term, before you could pretty much dump a few hundred thousand into the market and that would be enough to send it skyrocketing ( You could do this in the altcoin markets for example, with less actually because they aren't as well known ) but now it's going to be difficult because there's so many people trading it's going to require a big move for the price to go either way.

This is partly a good thing though, because people were bitching and moaning about stability a lot before, it will be interesting to see what happens during the stock market crash that is inevitably going to happen.