See:
https://blog.myheritage.com/2019/08/...by-myheritage/


"Our analysis of a huge cohort of 1.8 million anonymized DNA tests — the first of its kind in Jewish demography research — has revealed that the country with the highest proportion of Ashkenazi Jewish ethnicity after Israel is Hungary, and not the United States as was previously believed. After Israel, the top countries in terms of significant Ashkenazi Jewish ethnicity were Hungary and Russia, followed by Argentina, South Africa, Ukraine, and then the USA. This shows that there is a significant number of people in Hungary who have a Jewish heritage background that they do not acknowledge, are not aware of, or that their ancestors intentionally repressed."

" 7.6% of the 4,981 people living in Hungary who took the MyHeritage DNA test were found to have 25% or more Ashkenazi Jewish ethnicity (equivalent to having at least one grandparent who is fully Ashkenazi Jewish). This is a significantly higher percentage than the 3.5% observed in DNA test-takers living in the USA and the 3.0% in Canada."

"Hungary’s lead grows further at lower thresholds for Ashkenazi Jewish ethnicity. 12.5% of the people tested in Hungary have 10% or more Ashkenazi Jewish ethnicity, compared to only 4.7% of people in the USA and 4.0% in Canada. Meanwhile, 4.2% of people tested in Hungary have 50% or more Ashkenazi Jewish ethnicity (equivalent to having at least one parent who is fully Jewish), compared to 2.3% in the USA."


I don't know why this is controversial. Ashkenazi were a much bigger percentage of the population in eastern Europe than they are in the U.S., where all Jews form only about 5% of the population.

Then there's the fact that there was a lot of assimilation in Hungary, encouraged by the government.

Of course, the actual numbers might be a little lower, as people with some knowledge of Ashkenazi ancestry might be more likely to test.