No, much have changed since 2013.
Back then there was one exchange that had most of the volume. These days its different.
Especially with wall street getting involved and all those ETFs that are trying to get approved and listed on the stock markets.
With the existence of coin exchange sites from left to right, the circulating coins throughout the entire network is almost evenly spread and I have to agree with you. There's no way a pump and dump group could do this since Bitcoin's value is so really high and a group should be consist of BTC holders that has a tremendous amount of coins in their wallet which can manipulate its price from time to time. Bitcoin's movement and growth has changed dramatically with the continuous increase of people that was able to acquire BTC's. In fact, even Bitcoin hoarders has already gave up what they have as they can't resist to earn lots of profits.