The U.S. Federal Reserve ended last year with $4.49 trillion in assets, up $473 billion from the previous year as a result of its third round of quantitative easing. The central bank ended the bond buying program last fall.
The Fed's operating expenses fell to $6 billion from $6.1 billion in 2013, according to revised audited financials from the central bank.
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It sent a record $96.9 billion in interest income to the U.S. Treasury last year.
Additionally, it lost $2.9 billion on foreign currency assets in 2014. The dollar has climbed more than 22 percent against a basket of currencies in the last year.