Mainstream financiers like BlackRock CEO Larry Fink may claim that bitcoin is an “index of money laundering,” but a new report from Deutsche Bank AG says that this year’s bitcoin price surge is not the product of criminal activity, it’s Mrs. Watanabe.

As reported by Bloomberg, the Japanese branch of the German banking giant issued a note to clients attributing the bitcoin price’s dramatic fourth-quarter rally to ‘Mrs. Watanabe,” a term colloquially used to refer the archetypical Japanese retail investor: a housewife who manages her family’s finances with a shrewd eye.

That Mrs. Watanabe would embrace bitcoin so willingly may seem surprising given her cautious reputation, but that stereotype has not been true for some time now. Facing low domestic interest rates, many retail investors in Japan had become active forex traders over the past several decades — accounting for approximately 50 percent of all forex margin trading.

These investors see cryptocurrency trading as a natural corollary to forex trading, albeit with the opportunity to reap much larger returns. For instance, on bitFlyer — the highest-volume Japanese bitcoin exchange — traders can exercise up to 15 times leverage.

“We think that retail investors are shifting from leveraged foreign-exchange trading to leveraged cryptocurrency trading,” analysts led by Masao Muraki wrote.

Indeed, Japan has emerged as a major economic center for the cryptocurrency industry since the country passed bitcoin-friendly regulations earlier this year. According to some estimates, as much as 40 percent of all cryptocurrency trading is now denominated in yen — a phenomenon that was spurred by China’s crackdown on mainland cryptocurrency exchanges.

However, the report warned that, due to the compounded risks of trading on margin with assets that are already quite volatile, investors could quickly turn sour on cryptocurrency if the bitcoin price enters a bear cycle.

“The risk of incurring losses greater than margin is higher than in normal foreign-exchange trading, due to high intraday volatility,” the report said.

But the bank is not just concerned about cryptocurrency traders themselves. Noting that “speculation in cryptocurrency is growing to a scale that cannot be ignored,” the report said that the bank intends to research potential impact on the wider markets if the so-called bitcoin bubble should burst.