Tether is a superior cryptocurrency network. Tether limited run this network. Tether says that they are not a financial instrument. Tether also states that the owners of this digital currency did not have any contract base rights or guarantees against any losses. Tether Ltd or Tether cryptocurrency had to face many controversies because according to the users they didn't fulfill their promises. Tether's unclear relationships with banks affected its appearance. In 2018 this company's price dropped to $0.90. Because of this sudden fall, users lost their faith in their tokens. Tether claims that it takes US dollars on reserve to fulfill their customers' withdraw demand. But they failed to process all withdrawal requests on 2017. Thousands of tokens were stolen from Tether in 2017. It was a hard time for this company. But they combat all these challenges and on 19 Dec 2017, it re-enabled its wallet's use.