Bond investors love…stocks?

Getty Images

The rally in global stock markets has been so strong this year that even foreign exchange and bond investors tip the asset class to outperform over the next six months, Bank of America Merrill Lynch said on Thursday.

The bank conducted a survey of 75 bond and foreign exchange (FX) institutional investors this week, and found that over half (51 percent) named equities as the asset class with the largest upside for the next half-year.

(Read more: Peripheral bonds: How to play Europe's recovery)

In comparison, only 6 percent of the investors forecast that government bonds would outperform, and only 3 percent chose corporate bonds.

Global stocks listed on the MSCI All Country World Index have rallied at an annualized 22 percent this year, according to Bank of America, while several major bond classes have lost value. In particular, 30-year U.S. Treasurys have posted an annualized losses of 16 percent — the biggest decline since 2009.

"We have seen significant outperformance of stocks versus bonds this year… Therefore, we are not surprised that a majority of our fixed income & FX clients pick equities as their favorite asset class in coming months," said Bank of America analysts led by Michael Hartnett.

(Read more: The bond market's ticking time bomb)

Greek equities are this year's top performing assets to date, up 39.2 percent, according to Bank of America, while Indonesian government bonds are the worst performers, down 25.5 percent.

But despite this upward trend in equities, the decision by the Federal Reserve not to begin scaling back its stimulus program in September has seen investors move out of stocks and into bonds. The central bank surprised markets by announcing that it will continue to buy $85 billion worth of bonds each month.

The Bank of America analysts said that further asset allocation towards equities would require a stronger global economic recovery, as high liquidity and profit had decreased in importance for investors.

(Read more: A bond manager whosays all the selling is a good sign)

"We think the catalyst must now be higher growth," the report said. "The good news is that real estate prices (up across the world, bar Europe), purchase mortgage applications (at an eight-week high) and credit availability (lending to small business is up for the first time since 2008) all argue that GDP (gross domestic product) estimates are more likely to rise than fall, in our view."

—By CNBC's Katy Barnato