Question

Which type of credit card carries the most risk?

Secured with fixed interest rate

Secured with variable interest rate

Unsecured with fixed interest rate

Unsecured with variable interest rate

Answer 1

Secured cards have some kind of guarantee that any unpaid balance can be collected in case the borrower can't/won't/doesn't pay, and a fixed rate card has the same interest rate all the time (ignoring default rates and promotional rates).

Both are meant to reduce the risk of default (at least from the financial institutions point of view), so the riskiest credit card would be the unsecured with variable interest rate. From the consumer/borrower's point of view, the secured card with variable interest rate is the riskiest, as this has the potential to cost them the most if they can't/won't pay their bill.

tl,dr: unsecured variable for financial institutions, secured variable for individuals

Answer 2

Secured with fixed interest rate