In the second quarter of the year, one in which unlike in Q1 fund flows showed a persistent and perplexing outflow from US stocks and into European and Emerging Markets, a trading desk rumor emerged that even as institutional traders dumped stocks and retail investors piled into ETFs, a "mystery" central bank was quietly bidding up risk assets by aggressively buying stocks. And no, it was not the BOJ: the Japanese Central Bank's interventions in the stock market are familiar to all by now, and for the most part the BOJ keeps its interventions local, mostly propping up Japanese stocks, whether the Nikkei 225 or the Topix.

The answer was revealed this morning when the hedge fund known as the "Swiss National Bank" posted its latest 13-F holdings. What it showed is that, as rumored, the Swiss National Bank had gone on another aggressive buying spree in the second quarter, and following its record purchases in the first quarter, the central bank boosted its total equity holdings to an all time high $84.3 billion, up 5% or $4.1 billion from the $80.4 billion at the end of the first quarter.