Old addresses with a lot of funds are not that big a deal. If they have 1 like that they probably have more.
Not something to worry about the trading volume of BTC is on the order of 1.5 million coins a day. Having a few thousand more dumped into it is not something to worry about.
-Dave
We have seen this many times before and we will see more of this going forward, old Bitcoin wallets will keep on transacting because you don't expect them to leave their Bitcoin dormant forever, as most people who hold Bitcoin way back have a long-term goal to it some may place 10 years holding plans other can also have 20-year holding plans to at whateverr time the owner feels comfortable to move their Bitcoin around it's the choice and their money and it is sure ther made huge profits already considering the entry time and price.
5,000 bitcoins is not that huge to create any panic or discussion here, 1.5 million Bitcoin are traded daily and that is enough volume to accommodate any old wallet balance whenever their get offloaded into the market. I don't panic when I see such old. wallet balance movement only newbies do that and as for old members who are already experienced with such actions, I can only get excited that at least the dormant long abandon wallet is still active and that gives us the chance to take hold of then if the wallet owner injects those Bitcoin into the market, but at the moment we can't confirm if the Bitcoin we're transferred to an exchange wallet or a privately own cold wallet.