The number of complaints regulators have received in the first half of 2016 by financial consumers has increased, the European Securities and Markets Authority (ESMA) announced on Friday.

ESMA’s report reveals the number of complaints they received jump to more than 7,000 in the first half of 2016, compared with 5,152 for the same period in 2015.

In particular, ESMA says that the data indicates that complaints about investors’ charges are on the rise. It says, “…fees and charges are increasingly causing concern to retail investors, which is likely to be linked to their increased prominence in the current market environment of very low yields.”

ESMA reports that order execution accounted for 31% of complaints, another 19% involved poor disclosure, and 15% were related to unauthorized businesses.

Xomplaints relating to investment advice “have fallen markedly over recent years,” ESMA says. This may be due to measures taken both by various national regulators and the ESMA itself to address issues in this area, the regulators note.

In terms of products, ESMA reports that fixed-income product complaints are on the rise. “One clear trend was an increase in the proportion of complaints relating to bonds and other debt securities,” it says. By product, 20% of complaints involved fixed-income securities, followed by equities at 17%, derivatives (such as options, futures and swaps) also accounted for 17% of total complaints, and 15% involved contracts for difference.