It claimed that "the estimated wealth of the wealthiest 3 million American and Israeli Jews are estimated at more than $6 trillion concentrated mainly in the United States,[which is] more than twice the gross domestic product of all Arab countries, which the World Bank in 2013 estimated at 2.8 trillion dollars. The study shows that some of the wealthy Jews are committed to supporting Israel as a Jewish state financially by increasing donations, investments and supporting the Jewish youth in Israel and outside Israel, in addition to the economic expansion of Jewish power to most parts of the world thanks to investment in intelligence, innovation and creativity."
I have no idea how they calculated the $6 trillion. If it is true, it means that the richest 3 million Jews are worth an average of $2 million each. That's Jews, not Jewish households.
At any rate, the comparison is apples to oranges. GDP is the value of all goods and services produced within a nation in a given year, it does not reflect total assets that the people of that nation have. So, for example, Saudi Arabia by itself has $2.3 trillion in foreign assets alone. Clearly Saudi Arabia alone has more assets than $6 trillion if you include domestic assets.
Many of the other statistics in the article came from this YNet article about wealthy Jews in America,
Here are two of the photos that accompanied the article (along with one of Sheldon Adelson):
Because we all look alike!