The total value of U.S. securities class action settlements surged in 2018, according to a new report from a San Francisco-based consulting firm, Cornerstone Research Inc.

During the year, class action settlements totalled $5 billion (all figures in U.S. dollars), up from just $1.5 billion in 2017. The volume of settlements was essentially unchanged from the previous year (78 in 2018, down from 81 in 2017).

The jump in settlement value reflects, in part, a rebound from a very low reading in 2017, and a handful of settlements that topped $100 million in 2018, including a $3 billion mega settlement, the report notes.

Cornerstone reports that there was also a “notable uptick” in settlements that came in between $10 million and $50 million.

The average settlement amount jumped from $18.7 million in 2017 to $64.9 million last year. The median amount also more than doubled from $5.1 million to $11.3 million in 2018, Cornerstone says.

“Publicly traded corporations have reason to be concerned over the data,” Joseph Grundfest, a professor at Stanford Law School, said in a release. “Increased payouts may pressure insurance carriers to raise the rates they charge and the retentions they impose – which could be challenging developments for corporations, boards, and executives.”