THE BELOW ARE MY PERSONAL THOUGHT ON THE MATTER AND SHOULD NOT BE RELIED ON AS IT IS UNKNOWN TERRITORY
There have been suspicions about it right from the start. The fact that it is tied to something making it reliant on a third partys integrity is in itself sufficient reason never to handle it . The history of linking currency to something such as gold or the USD is filled with fraud . In this case they even have very limited access to the item they are linking the USD as US banks will not give it to them. Sooner or later the whole thing is likely to explode.
The result of that explosion we do not know but I take FUD centrals prediction of a 80% drop in the price of bitcoin with a grain of salt. They do not provide nor do they have access to the necessary figures to make that calculation to do so you need to be able to calculate the difference between the amount of tether out there (known amount) and the amount of USD actually held by them(unknown amount). Then have some magic way of working out the contagion effect of panic selling of bitcoin by those who do not even have tether.
I still think that straight after the fraud is proven(Its still only an accusation) Bitcoin will rise dramatically then fall dramatically before recovering. With luck a number of altcoins will become worthless as people steer away from any coin that reintroduces third party risk (actually there being one born every moment combined with a basic ignorance of what they are putting their money into means this is unlikely). The exchange issuing tether will probaley close down.
I CAN ONLY EMPHASIS STAY AWAY FROM TETHER SIMPLY AS A BASIC SAFETY PRECAUTION