Russia's benchmark stock index extended 2013 gains on the last trading day of the year as investors bet that two bomb blasts in the southern city of Volgograd won't hurt the economy.

The Micex Index added 0.3 percent to 1,499.62, bringing its increase in 2013 to 1.7 percent. That compares with a 5.3 percent drop for the MSCI Emerging Markets Index, Bloomberg reports.

The bombings at a train station and on a trolleybus killed at least 26 people within 24 hours shortly before the New Year. The attacks come as Russia prepares to host the Olympics next month in Sochi, a Black Sea resort close to the volatile North Caucasus region.

The Micex "rarely reacts to this kind of terrorist activity," Julian Rimmer, a trader at London-based CF Global Trading U.K. Ltd., said, according to Bloomberg. "They are usually one-off events which don't impact the economy in the long-term.

Russia's gross domestic product expanded 1.2 percent in the third quarter, the slowest pace since it saw a contraction in 2009.