Political and economic uncertainty is a key concern in the minds of investors, and there is no such thing as a "safe bet" anymore, chief exectutives told CNBC.
Uncertainty "is a governor on growth, " Thomas Finke, CEO of Babson Capital, told CNBC at the global summit on business growth at the Milken Institute in London.
"A lot of businesses are staying on the sidelines for a number of reasons. Number one is the uncertainty — around the euro zone crisis , around the U.S. election , and waiting to see how the transition occurs in China, " Finke said.
Finke, leader of a global investment management firm which manages $149 billion in assets, told CNBC that the U.S. "fiscal cliff" and potential major changes to the tax code — Congress must decide by the end of the year whether to raise taxes and increase spending cuts — was making businesses procrastinate over investment.
"It's easier to sit and wait to see what happens and whether there is an impact on the economy, " he said. "If they deal with it — if we get some positive news out of this — people will have more conviction to consume, which will give businesses more conviction to produce."
So-called "real assets" such as real estate are often flocked to in times of uncertainty, but Howard Marks, CEO of Oaktree Capital Management, told CNBC that they are not a safe bet.
"[Investing in] real assets is an example of the kind of simplistic formula that people resort to, but one of the things I try to emphasize is that in investment, there is no such thing as a 'good idea' or a 'bad idea' until you talk about price, " Marks said, citing London's booming property market that has bucked the downward trend in real estate prices seen elsewhere.
"The trouble is that people say that real assets are tangible and [thus] safe. [With real estate, for example, ] you could live in them and so they are 'safe', but does that mean that owning a house in London is good source of safety regardless of the price you pay?" Marks asked.
He added: "It can't be. If something is a good idea at $10 million, it's hard to believe it's an equally good idea at [$30 million]."
Marks told CNBC that indeed, no investment was safe.
"Sweeping generalizations are horrible, " he said, "Especially if made without regard to price."
—By CNBC's Holly Ellyatt