The digital currency market bubble is coming to an end; some believe that the markets have one pump left before a major decline, but regardless, the end is near. Several financial institutions and even Janet Yellen, the treasury secretary of the United States, recently released statements about the digital currency markets\u2013and none of those statements have been bullish. What are the experts saying? A recent survey from the Bank of America (BofA) shows that BTC is the most-crowded trade at the moment. In January of this year, BofA surveyed portfolio managers, strategists, and chief investment officers who collectively manage over $561 billion; 36% of them said BTC is the most crowded trade. The last time institutional investors considered BTC to be the most crowded trade was December 2017, during the era that many people call \u201ccrypto-mania.\u201d With that in mind, remember that BTC and the digital currency market crashed shortly after December 2017 and entered a two-year bear market.\u00a0 Deutsche Bank (DB) also conducted a survey from January 13-15. In the Deutsche Bank survey, 627 professionals were asked questions about financial markets; 56% of the respondents believed BTC is more likely to halve in value over the next 12 months, and on a scale of 1-10 regarding an asset being in a bubble, half of all respondents said BTC is a 10. Janet Yellen, the treasury secretary of the United States, recently said that, \u201cCryptocurrencies are a particular concern. I think many are used - at least in a transaction sense - mainly for illicit financing.\u201d And Barclays Private Bank chief market strategist Gerald Moser recently said that in regard to BTC,\u00a0 \u00a0While it is nigh on impossible to forecast an expected return for BTC, its volatility makes the asset almost 'uninvestable' from a portfolio perspective\u2026The performance of the cryptocurrency has been mostly driven by retail investors joining a seemingly unsustainable rally rather than institutional money investing on a long-term basis. This rally is not sustainable There is no way that an asset that rises by over 100% in less than one month can sustain that growth. Institutional investors and financial experts, who often look at investing a little differently than retail investors, know that the growth the digital currency markets just experienced can not last. On top of that, Janet Yellen\u2019s comments about digital currency may be alluding to how the Biden administration feels about digital currency markets.\u00a0 At the end of the day, the market action we have seen in the digital currency markets is not sustainable\u2013and many experts have beliefs that the digital currency rally will come to an abrupt ending, just like all financial bubbles do.