The Financial Industry Regulatory Authority and the Securities and Exchange Commission warned investors Monday to be wary of an increasingly popular way to borrow against their holdings called “securities-backed lines of credit” (SBLOCs).

"(These revolving lines of credit) might seem like an attractive way to access extra capital when markets are producing positive returns, but market volatility can magnify your potential losses, placing your financial future at risk," Gerri Walsh, Finra's senior vice president for investor education, said in an alert.

On the surface, SBLOCs are cheap and convenient ways to borrow because the interest rates are often less than bank and credit-card loans and some SBLOC lenders don’t perform credit checks. Additionally, these loans can be a way to avoid potential capital-gains taxes because SBLOC borrowers don’t have to liquidate securities to access money.

However, Finra and the SEC warn there are real dangers, including that borrowers could be forced to use other assets to help pay back the loans if they find they have to sell the securities in fire sales because of declines.

They also cautioned that some brokers and financial advisors are pushing the products because their firms give them additional compensation based on the amount of money customers borrow.