The ECB left interest rates unchanged at 0.75%, as expected.
Investors applauded ECB president Mario Draghi as he announced details of a new bond-buying program to help stem Europe's debt crisis.
Draghi said the ECB is prepared to make "outright monetary transactions," also known as OMTs, in the secondary market for euro-area sovereign bonds.
"The ECB is going to act as a backstop for sovereigns," said Nick Stamenkovic, fixed income strategist for RIA Capital Markets in Edinburgh, Scotland. "Consequently, initial reaction is more confident that these actions will relieve some of the tensions that have overhung the market for some time."
Stamenkovic said the ECB's "forceful stability program" requires the participating nations to stay within certain parameters of fiscal prudence.
"They must attach themselves to fiscal and structural reforms," he said. "Otherwise, the ECB has the power to remove that support."
|What stumps Warren Buffett? Minimum wage|
|Water becoming more valuable than gold|
|GM's $1.3 billion recall cost wipes out profit|
|Will 7 Apples a day keep the bears away? - The Buzz|
|Ex-Wal-Mart CEO Duke retired with $140 million|
|Overnight Avg Rate||Latest||Change||Last Week|
|30 yr fixed||4.24%||4.32%|
|15 yr fixed||3.25%||3.36%|
|30 yr refi||4.28%||4.31%|
|15 yr refi||3.30%||3.34%|
Today's featured rates: