The Securities and Exchange Commission levied $16.3 million in penalties against Moody’s Investors Service last week to settle charges involving internal control failures and failures to clearly define and consistently apply credit rating symbols. The bulk of the fine relates to more than 650 non-agency mortgage-backed security ratings issued between 2010 and 2013 that subsequently had to be corrected. Sens. Mark Warner, D-VA, and Mike Rounds ... [Includes four briefs]