mother of all bubbles

国債の外国人所有比率が史上最高となりました。欧州危機の懸念のために、まだ「安全」と言われる日本円にマネーが流入しているのがその理由ですが、これがはじけたら...。そんな警告を専門家たちが発しはじめました。
motherはここでは「源、本源、大元」という意味で使われています。政治家も党利党略に血道をあげている場合ではないと思いますが...。（UG）

Japan risks to create “mother of all bubbles”

Japan has increasingly attracted foreign money, as the country is seen as a financial safe haven compared to troubled Europe, but there are voices that warn for an upcoming “bubble”.

Foreign demand for Japanese Government Bonds (JGB) reached a record high in June, at nearly $1 trillion, the Bank of Japan announced. Foreigners owned about 8.3 percent of all issued JGBs at the end of March, the highest level since the central bank started to keep track of the data, back in 1979.

The high level of foreign ownership of Japanese debt is however posing risks, if non-residents start asking for higher returns, while the government is already pressed by a huge public debt, analysts warn.

http://www.tokyotimes.co.jp/2012/japan-risks-create-mother-bubbles/