Fed Chair Janet Yellen leaves her post after four years this week, and during her tenure it was smooth sailing for stocks, with tech shares doubling and financial stocks springing back to life.

The Nasdaq 100 gained 97 percent and emerging market stocks soared, with the Argentine Merval jumping nearly five times and the Brazilian Bovespa rising 80 percent. The Dow is up 67 percent and the gained 59 percent.

Sources: Reuters, FactSet

It was just over nine years ago that the Federal Reserve took the fed funds rate to zero during the financial crisis, but it was the Yellen Fed that brought it back, raising interest rates for the first time since the financial crisis in December 2015. The Fed has since hiked four more times, and during Yellen's tenure, the S&P financials, big beneficiaries of higher rates, rose 74 percent. The fed funds target rate range is currently 1.25 to 1.5 percent.