Mark Yost has served as a lieutenant colonel in the judge advocate general’s corps, as a federal prosecutor and most recently as a senior counsel in the Securities and Exchange Commission's Foreign Corrupt Practices Act unit in Washington, DC.
A 1980 graduate of the US Coast Guard Academy, Yost studied marine science and was twice voted class president. He served in various positions with the coast guard until leaving active service in 1995.
Yost earned his law degree from Georgetown University Law Center. From 1995 to 1997 he served as a clerk to US District Judge Joyce Hens Green in Washington, DC, assisting her oversight of cases related to the collapse of Bank of Credit and Commerce International.
He joined the Justice Department in 1997 as a trial lawyer in the tax division, where he served until 2001. He then joined the DOJ's asset forfeiture and money laundering section (AFMLS), where he served until departing for the SEC in 2007.
As a trial lawyer in AFMLS, Yost prosecuted former executives at National Century Financial Enterprises, once the nation's leading lender to healthcare providers. The Ohio company collapsed in 2002; the former executives were indicted on charges they defrauded investors of more than US$3 billion.
Yost also prosecuted Robert Stein Jr, the former comptroller for the coalition provisional authority in Iraq. In 2006, Stein pleaded guilty to bribery, conspiracy, money laundering and other charges concerning a scheme to steer reconstruction work to a corrupt contractor. While at the DOJ he also investigated counterfeiting of US currency in Asia, counterfeit goods smuggling and money laundering.
After joining the SEC in 2007, Yost was part of the team that investigated Citigroup Global Markets and UBS Financial Services for misleading investors about the risks associated with auction rate securities. In the largest settlement in the agency's history, the firms agreed in 2008 to buy back nearly US$30 billion in auction securities from customers who invested in them. Yost has also represented the SEC in insider trading and investment fraud cases.
Yost qualified to compete as a triathlete for the US at the 2011 world championships in Beijing, China, where he placed 15th overall in the 50 to 54 age group. He also distinguished himself as a wrestler at the US Coast Guard Academy. Yost served as a reserve judge advocate general in the US Air Force between 1996 and 2008.