You can check whois bitfinex.com: Creation Date: 11-oct-2012
Archive.org has the first snapshot at February 22, 2013, but for some reason I get the
April 5, 2013 snapshot when I click it.
They must have started somewhere between these dates.
Will you share the article here?
Awesome, thanks. I will certainly be sharing the article. It's an attempt to discover more about the early development of Bitcoin exchanges which are, frankly, really hard to find info on.