Janet Yellen is in the hot seat. The Fed chief has the unenviable task of deciding whether the U.S. economy is finally healthy enough to take it off life support.
Economists believe the Fed will in fact raise interest rates in September for the first time in nine years. While a rate hike would represent a vote of confidence in the economy, it's also causing nervousness.
Yellen has been pretty explicit lately that a rate hike later this year is likely.
Still, there is concern that the Fed may be moving too quickly. Those worried about the economy believe a premature rate hike could stunt growth, hurting stock prices in the process.
On the flipside, some fear the Fed is waiting too long. If a rate hike doesn't happen soon, the economy could overheat, fueling inflation. In that scenario, the Fed would have to raise rates more aggressively in the future, potentially killing the bull market.
Related: Yellen still thinks Fed will raise rates this year
