Bitcoin’s tumultuous rise above $11,000 – then the highest value the coin had ever reached – last Tuesday was quickly muddied as it dropped nearly $2,000 the very next day. Now, the world’s most famous crypto-currency is back on the up and up, but leading economists have warned once again about Bitcoin’s instability.

The harshest call was made by Nobel laureate and former Chief Economist of the World Bank Joseph Stiglitz, who asserted that Bitcoin, “ought to be outlawed.” Stiglitz rallied against the crypto-currency’s instability during an interview with finance news outlet Bloomberg TV. He added: “Bitcoin is successful only because of its potential for circumvention. It doesn’t serve any socially useful function.”

A similar call was made by Robert Shiller, another Nobel Prize winning economist, who told a finance conference in Lithuania: “It’s such a wonderful story. If it were only true”.

Big brands and names from Wall Street have also voiced their condemnation surrounding the currency. Following the coin’s rise above $11,000, Goldman Sachs CEO Lloyd Blankfein told Bloomberg that the currency only acts as, “a vehicle for perpetrating fraud.” Meanwhile, billionaire investor Carl Icahn said on American finance network CNBC that its rise, “seems like a bubble.”

The currency has also previously attracted derision from CEO of JPMorgan Jamie Dimon, who branded it a ‘fraud’ that would, “eventually blow up,” back in September. Magnate Warren Buffett has also warned of a ‘real bubble,’ surrounding the currency.

But some experts have argued that recent gains for Bitcoin are being driven by the expectation that Wall Street is in fact gearing up to invest.

CME Group, which owns the Chicago Mercantile Exchange (a market for financial instruments such as contracts on the future price of assets like metals), has noted that it will list bitcoin futures in mid-December. Nasdaq, meanwhile, has claimed that it plans to launch bitcoin futures next year.

Dimon’s slamming of Bitcoin was also famously followed by JPMorgan’s mass-purchase of 19,102 Exchange-Traded-Notes (ETN), which track the price of Bitcoin, and are valued at around 95 Bitcoins, about $500,000 each back in September. The timing of the transaction led to speculation that the bank may have deliberately attempted to undermine Bitcoin’s value in order to purchase it at lower rates.

Despite Dimon’s comments, JP Morgan also remains a leading member of the Etherium Enterprise Alliance.