Shares of Electronic Arts Inc. plunged 18% Thursday morning, the biggest decline since 2008, after the gaming company warned its financial results would be weaker than expected due to poor sales results of two titles released over the holidays.

Electronic Arts shares sank more than 15% on Thursday, tripped up by a surprise slowdown in spending on the soccer franchise that has shaped its gaming empire.

Electronic Arts slashed its full-year guidance on Wednesday, blaming the shortfall on underperforming games, in particular, its soccer franchise.