One in ten euro zone households have bought crypto-assets such as bitcoin, with the rich only slightly more likely to own some than the poor, a European Central Bank study showed on Tuesday.

With the "crypto" market in turmoil, authorities are trying to gauge whether gyrations in this relatively new corner of the financial system could burn a hole in household budgets.

The ECB's Consumer Expectation Survey found that an average of 10% of the households in the six countries where the poll is conducted own crypto-assets, with the proportion ranging from 6% in France to 14% in the Netherlands.

Around 37% of respondents reported owning up to 999 euros ($1,065) worth of crypto, with 29% holding between 1,000 euros and 4,999 euros and 13% between 5,000 euros and 9,999 euros. The balance had invested more than that.

In all countries, the richest 20% of respondents was most likely to own crypto currencies but a greater proportion of lower-income households reported owning digital coins than those in the middle ground.

"On average, young adult males and highly educated respondents were more likely to invest in crypto-assets in the countries surveyed," the ECB said. "With regard to financial literacy, respondents who scored either at the top level or the bottom level in terms of financial literacy scores were highly likely to hold crypto-assets."

Repeating its longstanding line, the ECB said those assets were unsuitable for most retail investors and urged European Union authorities to approve new rules on crypto assets "as a matter of urgency."

The data, released for the first time on Tuesday, was cited in an article published as part of the ECB's Financial Stability Review.

Launched in 2020, the ECB's Consumer Expectations Survey is carried out monthly in Belgium, France, Germany, Italy, the Netherlands and Spain. It is still in pilot mode and results are not published in full by the ECB. ($1 = 0.9376 euro)

(Reporting by Francesco Canepa in Frankfurt Editing by Matthew Lewis)