Getty Images/iStockphoto The number of securities class-action lawsuits filed in the first half of 2021 has fallen considerably from the levels in the second half of 2020, according to a report released Wednesday by Cornerstone Research and the Stanford Law School Securities Class Action Clearinghouse. Plaintiffs filed 112 securities class-action cases in federal and state courts in the first half of 2021, down 25% from the 150 cases filed in the second half of 2020, according to the report, "Securities Class Action Filings — 2021 Midyear Assessment." This marks the lowest number of filings since the first half of 2015. The report attributed the decline in filing activity to a 66% drop in filings related to mergers and acquisitions compared with the second half of 2020. Of the cases filed in the first half of the year, only 12 were M&A filings. The number of federal and state court filings alleging claims under the Securities Act of 1933 also continued to decline.