Former Federal Reserve Chair Janet Yellen had some harsh words for Bitcoin enthusiasts, labeling the cryptocurrency “anything but useful” during a speech Monday.

Yellen gave an interview at the 2018 Canada FinTech Forum in Montreal, Quebec, Canada. The news was first reported by Kitco:

Finally, on cryptocurrencies, Yellen said that coins like bitcoin are not considered legitimate currency, owing to their lack of ability to store value, and limited scope in everyday transactions.

“It has long been thought that for something to be a useful currency, it needs to be a stable source of value, and bitcoin is anything but. It’s not used for a lot of transactions, it’s not a stable source of value, and it’s not an efficient means of processing payments. It’s very slow in handling payments. It has difficulty because of its very decentralized nature,” she said.

CoinTelegraph then picked up the quote and followed with some additional commentary from Satoshi Portal CEO Francis Pouliot, who slammed Yellen on social media, describing her words as:

“The Official NPC [non-player character] guidelines to Bitcoin FUD, courtesy of the FED.”

At a press conference in December of last year, Yellen similarly called Bitcoin a “highly speculative asset” and “not a stable source of value.” She also noted that the Fed was not “seriously considering” the concept of a state-issued digital currency at that time.

Yellen’s speech Monday echos not only her own previous comments on crypto, but also those made earlier this month by economist Nouriel Roubini, an outspoken cryptocurrency naysayer who foresees the entire ecosystem failing.

Commentators have taken Roubini to task over his comments, arguing his lack of understanding of decentralized cryptocurrency has led him, like Yellen, to draw false conclusions about its resilience.

“I can see a bubble when there is one – and to me, this entire space has been the mother and the father of all financial bubbles and now it’s [going to] burst,” he told Cointelegraph during an appearance at BlockShow Americas in August.