Mounting worries over problems in Greece, Puerto Rico and China, as well as looming concerns over possible interest rate increases at home, have prompted advisors to switch to more cash-heavy allocations for their clients' portfolios.

Advisors have been allocating fewer assets to both equities and bonds, according to the latest findings of our Global Asset Allocation Tracker.

Wealth managers say many clients are nervous and losing confidence with those asset classes in the face of both new and recurring problems.

One financial planner says clients were "spooked" by recent volatility and potential threats posed by issues in Greece. Such worries have led some wealth managers to boost the cash portion of clients' portfolios.

"Obviously Greece was on everybody's mind, and still is. Cash seems to be king in this environment for now," one advisor says.

Another advisor says concerns over rising interest rates, as well as Puerto Rico's continuing troubles, have contributed to a reticence to buy bonds.

Despite these worries, some advisors continue to advocate moving more assets into global equities, particularly in Europe. But getting clients to see the advantages isn't easy.

"Greece is presenting a nice buying opportunity in the stock market, but people are a bit gun-shy to jump in right now," one advisor says.

The tracker, which surveyed 320 advisors, uses a baseline of 50. Readings of more than 50 indicate increases and less than 50 indicate declines.