However, the immediate reaction for traders was to sell the euro, and that euro selling only picked up steam throughout the day; the currency plummeted to an 11-year low against the U.S. dollar, breaking the $1.14 threshold.
While the ECB isn't admitting that a weaker euro is the desired effect, it is certainly a helpful and quick way to stimulate growth through more competitive exports.
Read MoreEuro falls to fresh 11-year low on ECB decision
"Bottom line, as I doubt even the ECB believes that this news will directly increase bank lending, it is likely all about further weakening the euro," wrote Peter Boockvar of The Lindsey Group after the announcement.
Some central banks have been more explicit about wanting their currencies to weaken to defend themselves from stronger currencies ahead of the ECB's major move and the weaker euro.
The Danish central bank cut its main interest rate to minus 0.35 percent Thursday morning, from minus 0.20 percent, the second rate cut in a week. Denmark pegs its currency, the krone, to the euro, so it is trying to keep flows from racing out of the krone ahead of ECB action and a weaker euro.
Switzerland similarly anticipated a weaker euro and took a momentous and shocking step of ending the cap of the Swiss franc.
"Abandoning it now would arguably be less costly than defending if, as it seems likely the euro will continue to decline and the dollar will continue to appreciate," wrote Marc Chandler of Brown Brothers Harriman.
Read MoreECB needs to buy more bonds than Fed: CIO
Canada this week shocked markets by cutting interest rates for the first time since 2010, citing the sharp plunge in oil and its negative impact on the Canadian economy, which depends on oil exports.