The money currently floating the prices is from both the profits that have been taken and money that was already sitting on the sidelines. Sure, the capital can come at some point to continue to keep us up here, but for now its not here to stay without a day to day change in the 10-30% range, whether it be up or down. The people who have a significant amount of coins switched to a significant amount of fiat and are currently going in and out. I couldn't have believed that the money I spent in January and February would be what it is now if you had told me. There are very experienced traders here and they will manipulate to their satisfaction.
Since your so worried about what the owners of those 6 wallets are going to do, why don't you just sell your btc now? Get out while you can. Put your money where your mouth is.
Of course someone with a gazillion btc could put in a gigantic market order. That could happen any day. It's just extremely unlikely given a myriad of reasons.
But worrying about it is not a factor in trading the market. I live in LA. We could have an earthquake tomorrow. But I don't change my life accordingly.
So go ahead sell and get out if you are really concerned with a dump.
Panic buying shall ensue shortly. 
