Throughout 2011, 2012, and 2013, Life Systems, Inc. reported double-digit increases in earnings in each of its periodic filings with the SEC. In each of the three calendar year annual reports Life Systems' outside auditors reported there were significant weaknesses in Life Systems' internal controls and each of the audit opinions stated the internal control weaknesses were "unremediated." Nonetheless, the auditors provided an unqualified opinion to the financial statements. As a result of a whistleblower's disclosures, in July 2013 the SEC launched an investigation of Life Systems; soon thereafter Life Systems announced it would restate earnings for each of the three prior years and that it was terminating its CEO and CFO because of "a lack of confidence in their stewardship of the firm." In early August 2013 a securities fraud class action was filed against Life Systems and its auditors seeking damages on behalf of investors who had purchased Life System shares between March 2011, the release date of the admittedly misleading 2011 quarterly report, and August 2013. How should the district court respond to a motion to bar claims by investors who purchased before August 2011