Photo: Reuters/Benoit Tessier

ECB President Mario Draghi tried to reassure investors yesterday that there is “no systemic danger” from bubbles, but it’s hard for some to shake the feeling that something’s going to burst.

Bloomberg asked multi-asset fund managers which “bubbles” they are most about:

Junk-rated bonds: “Money managers overseeing about $1.1 trillion have said in the recent past that they are cutting exposure to the asset class. High-yield bonds typically respond more violently than other assets to market shocks because investors tend to cut the riskiest bets first.”

High-grade credit: Schroder Investment Management’s Remi Olu-Pitan, agrees with former Fed chair Alan Greenspan: “The average U.S. pension plan is still trying to generate a return of 7.5 percent,” Olu-Pitan said. “They can’t put everything in equities to generate that return, so there’s a wall of money going into debt to get that extra yield. If that starts to unravel, everything unravels and there’s nowhere to hide.”

Bitcoin: A Chinese ruling this week to ban initial coin offerings, a popular means of fundraising for startups, briefly took the edge off the rally, clipping it 11 percent on Sept. 4. Mark Mobius, executive chairman at Templeton Emerging Markets Group, said in a recent interview that cryptocurrencies are getting “out of control and it’s going to attract the attention of governments around the world.”

China? Yes, some investors just can’t seem to shake their fears of China: “Like many investors before him, Legal & General Investment Management’s John Roe sees China as the biggest threat. Concerns about the country’s debt pile have ebbed and flowed in the past few years as investors try to grasp how much control the country’s leadership has on capital flows.”