Earlier quoted context omitted.
Tether is not an ICO and quite clear what it does. It is supposed to be a token that pegged to USD to facilitate the moving of USD via the blockchain instead of having to bother with the pain and fees of banks. Its market cap rises as more USD is deposited into their banks.
Sadly there is a lot of red flags indicating that this is not the case, they haven't had banking since April so there are no way to deposit funds to them for regular users at least. Also, one employee from Bitfinex suggested on reddit that Tether is funded by crypto deposit to them and not USD...
They've claimed they are ready to release audit details for 2+ years (no audit), and the founding team has also gone on the record about wash trading and other fraudulent financial activity.
Additionally, Bitfinex had some 'flash crashes' that wiped out people's margin accounts. Some believe the flash crash was caused by Bitfinex themselves on purpose to accomplish this exact goal.
Stay up to date at https://www.twitter.com/bitfinxed & https://reddit.com/r/bitfinex