In this article, I'll review the most popular fixed-income securities, the fixed-rate preferred stocks, sorted into several categories. There are 359 issues in our database that trade on primary exchanges, excluding the convertible preferred stocks, 60% of which are part of the biggest ETF for fixed-income securities: the iShares Preferred and Income Securities ETF (PFF). As we can see in the chart below, half of the PFF's market capitalization consists of fixed-rate preferred stocks, which also corresponds to almost half of the fund's holdings. This means that we are talking of around 7B