The U.S. Federal Reserve singled out a dramatic rise in the price of cryptocurrencies in its overall assessment of the stability of the financial system, according to Bloomberg, which said it's the first time the central bank has ever done so.

In its semiannual Monetary Policy Report, the Fed told Congress "the surge in the prices of a variety of crypto assets" reflects investors' increased appetite for risk. While Fed officials have discussed crypto before, they have seldom, if ever, used the asset class as a benchmark to consider broader market conditions.

Small shifts point to the Fed giving crypto a closer look. Top brass have met with key industry figures in recent months as they prepare to tackle more questions about crypto, such as how to proceed on a digital dollar project.

Even so, one small shoutout doesn't amount to a sea change. The 69-page report declined to elaborate further on crypto assets or their resiliency, prospects and impact on monetary policy. It bundled the mention within a broader section on the price of "risky assets," sandwiched between housing prices and Treasury yields.

"Asset prices may be subject to significant declines should investor risk appetite fall, interest rates rise unexpectedly or the recovery stall," the section ended.