With stocks hovering around all-time highs, many are wondering if this asset class is the next great bubble ready to burst.

But stocks aren't the only things that look frothy. There seems to be a lot of other asset classes that sure look like bubbles.

We've compiled the assets analysts now believe are flashing warning signs of over-inflating.

If you think we reached peak bubble-calls last spring when Robert Shiller diagnosed a "bubble on bubbles," think again.