700BTC buy in finex.
I feel pretty confident. Thank fuck I took in a long position yesterday at $465.

Looks like net=0 on that. Sell of 683 followed by a Buy of 683. Unlikely its just a coincidence.
Why would anyone sell at 691 and then buy at 697... unless they thought that there deliberate dump did NOT work, and they were going to miss the train?... but looks way too soon in time (only 2 minutes between the sell and the buy)
It does not have to be one selling and then buying.
It could be the same guy selling in both thrades, alternatively, the same guy buying. When you sell, you have the choice to accept an offer or place an offer that is later accepted by someone else. It is quite common for a trader to buy or sell the same quantity repeatedly. It is even common to identify the trades with odd numbers, like repeatedly buying f.ex 1.0035 BTC. It is the same with shares of equity. It could be a secret language between traders. Culture, in other words.