Ever worry that your retirement plan won't leave you with enough money to enjoy your golden years? You have good cause for concern, according to John Oliver. In the latest episode of Last Week Tonight, the HBO host took a look at the fees that are probably deflating your retirement dreams.

In many cases, while interest on your investment accrues, so do the compound fees for managing your portfolio. Depending on your plan, you could be losing up to two-thirds of your investments over the years. "So think of fees like termites," Oliver says. "They're tiny, they're barely noticeable and they can eat away your fucking future."

Your portfolio might be in big trouble if you've staked your retirement on "actively managed funds" - savings plans that involve analysts picking stock investments for you. The active managers present themselves as stock-savvy experts, but Oliver surfaced a study that suggests you might better off letting your pet handle your stock options.

"The problem with active management is that even many Wall Street experts find it difficult to consistently beat the market," Oliver explained. "And there is sometimes embarrassing evidence of this - like when a group of professionals were pitted in a stock-picking challenge against a cat named Orlando."

The feline outperformed the pros even though he picked stocks by throwing a toy mouse at a list of companies and investing in whichever one it landed on. For more on Orlando the cat, and the many ways that you're retirement plan might be leaking money, check out the full segment.