Cryptocurrency markets, after months of relative calm, are melting down all over again. Bitcoin crashed through its longtime floor of $6,000 and digital tokens of all types fell more than 10% in the past week.

The one exception has been so-called stablecoins, virtual currencies designed to maintain a fixed value of $1. In theory, they should be a safe haven from the larger crypto carnage. But will they hold up?

So far, the stablecoin situation has been reassuring. Three of the biggest—Paxos, TrueUSD and Circle-backed USD Coin—are actually trading a cent or two above $1. That’s the good news.

The bad news is the largest stablecoin of them all, Tether, is flashing a giant warning sign. As the Financial Times’ blog Alphaville notes, Tether has been “breaking the buck” since October and is currently underwater at 98 cents.

In theory, this shouldn’t happen. That’s because, if Tether is truly worth $1, arbitragers will swoop in and quickly drive it back to its baseline price of a buck. That’s not happening, which means something is wrong.

Word that something is fishy about Tether will not be news to anyone familiar with it. Critics have long decried the refusal of the Tether team to provide a proper audit to prove they are backing the currency with real dollars. And now come reports that its new banking partner, Bahamas-based Deltec Bank, is a dodgy outfit accused of money laundering.

More troubling still: Bitfinex, a cryptocurrency exchange tied to Tether, appears to have put in stiff new withdrawal fees for large investors that want to cash out their crypto holdings. As cryptocurrency blog News BTC notes, folks are already asking if this move is intended to halt a full-blown run on Tether, which is reportedly under attack from speculators.

All of this raises the question of what happens if another speculative attack proves nothing is pegging Tether to the dollar, and the price goes into free fall. If it turns out the true value of Tether—currently the eighth biggest cryptocurrency—is 75 cents or 50 cents or less, it could deliver a shock to the crypto markets that makes this week’s wipeout look like a hiccup.

The bright side is other stablecoins do appear to be backed by dollars on a one-to-one basis. Still, they are hardly a great place to park your money. At a time when even a simple savings account can earn you 2%, stablecoins pay nothing in the way of interest. What’s more, there are transaction fees to acquire them and, right now, the respectable ones are trading for a cent above the dollar.

All in all then, stablecoins sound a rotten investment—unless, of course, you compare them to the rest of the crypto market right now.

度过了较为平静的几个月后，数字加密货币市场再次全面崩溃。比特币跌破了6000美元的长期底部，而且上周所有加密货币都下挫了10%以上。

唯一的例外是所谓的稳定币，这种虚拟货币的设计宗旨是保持1美元的固定价值。在理论上，当加密货币全面暴跌时，它们应该成为避风港。但它们能坚持得住吗？

到目前为止，稳定币的情况都还让人安心。三大稳定币—— Paxos、TrueUSD和加密货币金融公司Circle支持的USD Coin的价格实际上都有1.01或1.02美元。这是好消息。

但坏消息是规模最大的稳定币Tether发出了醒目的警示信号。《金融时报》旗下的博客Alphaville指出，Tether早在今年10月就已经“跌破1美元”，目前的价格为0.98美元。

理论上不应该出现这样的局面，如果Tether确实值1美元，那么套利者就会趁虚而入并迅速将其价格重新推上1美元的基准线。但实际情况并非如此，那就是说出了问题。

对熟悉Tether的人来说，说它暗藏玄机不是什么新鲜事。长期以来，批评人士一直在指责Tether团队，因为他们拒绝提供正当审计结果，以表明自己是在用真金白银来支持这种加密货币。现在又有报道称，Tether团队的新合作银行，总部设在巴哈马群岛的Deltec Bank是一家涉嫌洗钱的“狡猾”机构。

问题还不止这些——和Tether关系密切的加密货币交易所Bitfinex，看来已经为打算将加密货币套现的主要投资者新设置了严格的提款手续费。正如加密货币博客News BTC所述，人们已经开始质疑此举是否意在防止Tether遭到全面挤兑，据说投机者已经对Tether下手了。

所有这些带来的问题是，如果新一波投机证明Tether并无盯住美元的手段，那会出现什么情况呢？倘若实际情况证明目前的第八大加密货币Tether的真实价值为0.75或0.50美元，或者更低，那么由此给加密货币市场带来的冲击可能会让本周的暴跌看上去就像“挠痒痒”。

好的一面是其他稳定币看来确实得到了美元的等额支持。但它们绝不是投放资金的理想对象。现在就连普通储蓄账户的利率都达到了2%，稳定币却不产生丝毫利息。另外，购买稳定币还要支付手续费，而眼下这些“受尊敬”加密货币的价格只有1美元零1美分。

综上所述，稳定币听上去是一笔失败投资——当然，除非大家拿它们跟目前市场上的其他加密货币相比。（财富中文网）

译者：Charlie

审校：夏林