Ah I missed the different name. Thanks for the clarification. I was thinking of comments I've seen before where people say that if you have 100 bitcoins you'll have a hard time converting them to (e.g.) $700k cash.
If you put a sell order at 7,000 with a volume of 100, it would (likely) cause a flash crash
You can see flash crashes all the time when someone offloads a bunch of coins without balancing across exchanges.
Plus, you would have to find quite a few people that wanted to buy coins @ 7,000 and finding them before your order causes a flashcrash isn't likely.