Aug 20 (Reuters) – Cryptocurrency-related stocks surged on Thursday, a day after the U.S. Treasury Department said it would support more ​long-duration bonds, boosting risk assets, and as U.S. President Donald Trump urged Congress to pass legislation establishing ‌clear rules for digital assets.

The Treasury’s move to double buyback sizes for long-duration debt came after a major bond selloff pushed the 30-year Treasury yield to its highest level since 2007. Higher yields are typically a negative for risk assets like cryptocurrencies ​because they increase the returns on safer investments.

While the Treasury’s intervention was relatively small and offered only ​short-lived relief for bonds, it nevertheless provided a positive…