Here are the top cryptocurrency stories of the week:

Tether's Lawyers Say that the Stablecoin Is Only Partially Backed by Dollars Lawyers representing the dollar-denominated stablecoin Tether released a set of documents that indicated that the stablecoin was only 74% backed by U.S. dollars. This runs counter to the assertion made by executives at Tether, who have continually insisted that their currency is fully backed by dollars. The lawyers were forced to release the documents because of a request by the U.S. Attorney for New York in an unrelated matter.

Facebook Is Seeking $1 Billion in Investment for Its Stablecoin Social media conglomerate Facebook is seeking $1 billion in investment for a stablecoin it is reportedly developing. The company is also in discussions with both MasterCard and Visa in regards to the currency. The currency will be called FB Coin, and is intended to be used by the company's users for making payments on Facebook Messenger, Instagram and WhatsApp.

Elon Musk and Vitalik Buterin Engage in Ethereum Discussion on Twitter Early in the week, Tesla CEO Elon Musk posted a cryptic tweet that simply said: "Ethereum." This led to a back-and-forth discussion with Ethereum founder Vitalik Buterin on the social media platform about future possible developments of the digital currency. Buterin not only listed 5 future projects he would like to see developed using the currency, but he also invited Musk to DevCoin, which takes place later this year.

Bakkt Acquires DACC This week, Bakkt — which operates an institutional digital currency trading platform — acquired Digital Asset Custody Company (DACC), which offers cryptocurrency custodial services. Bakkt further announced that it was applying to New York State's Department of Financial Services to become a trust company, which will let the company offer custodial services for digital assets.

Iota Partners with Jaguar Land Rover Cryptocurrency Iota announced a partnership with British car manufacturer Jaguar Land Rover. The partnership will allow the car company to give its customers Iota currency in exchange for customers providing it data about vehicle performance and road conditions.