About four hours into the final day of trading, shares in Citigroup (NYSE:C) are up 2.9% for the week on strong second-quarter earnings and soothing words from the Fed.

Strong numbers, soothing words
On Monday, the country's third-largest bank grew its net income by 42% year over year for the second quarter of 2013, and raised its total revenue by 11% year over year. Earnings per share were $1.34, up from $0.95 a year ago.

Those reassuring numbers from Wall Street were followed by some reassuring words on Wednesday and Thursday from Federal Reserve Chairman Ben Bernanke. Testifying before Congress on U.S. monetary policy for what is likely his last time as chairman, Bernanke reiterated that quantitative easing would not be implemented until the American economy is strong enough to get by without it.

Foolish bottom line
The issue of exactly when QE would be tapered back, and the havoc it might wreak on the U.S. economy, has been a touchy one for investors for most of the year, but especially since June 19, when Bernanke laid out a specific timetable for such a process.

Yet after some initial volatility, equity markets seem to have adjusted to the inevitable. And this week's testimony by Bernanke had a positive effect on the markets -- including Citi -- though without a long enough lasting effect to carry through to today: All three major indexes are currently in the red, along with Citi, Bank of America, and JPMorgan Chase. Somehow, Wells Fargo is managing to just keep its head above water.

But strong second-quarter earnings are the driving force behind Citi's big week. Forty-two percent income growth is always a welcome sight for investors, but the corresponding 11% revenue growth is what really makes that first number so appealing to the eyes and to investor portfolios. High income growth without strong revenue growth is rarely sustainable; it usually means cost-cutting, and you can only cut so much fat before you start cutting into muscle.

Also of note from Citi's Q2 results is where that revenue growth is coming from: overseas. Of the Big Four banks, Citi is the most committed to being global. For Q2, more than 50% of total revenue came from overseas, and Citi grew its international consumer-banking business by 4%. The U.S. is a mature market, and even though emerging markets have fallen on hard times right now, it's inevitable they'll begin growing again, and when they do, Citi will be well positioned to capitalize on that growth.