After working long hours over many months crafting new rules for Wall Street, a number of government regulators are switching sides to work for the firms that will have to follow and interpret them.

Whenever there is a major policy change in Washington like the 2010 Dodd-Frank financial overhaul, it enhances the marketability of government employees with specialised skills and contacts. But in the past, it was officials at the Securities and Exchange Commission, the Federal Reserve and the Treasury Department in particular who found their expertise and contacts most highly valued in the financial industry.