(WASHINGTON) — Mary Schapiro will step down as chairman of the Securities and Exchange Commission next month after a tumultuous tenure in which she helped lead the U.S. government’s regulatory response to the 2008 financial crisis. President Barack Obama designated Elisse Walter, an SEC commissioner, to replace Schapiro. Schapiro will leave Dec. 14, the SEC said Monday. She was appointed by Obama in the midst of the worst financial crisis since the Great Depression. She took over after the agency failed to detect the Bernard Madoff Ponzi scheme.