Shares of Dollar Tree Inc (DLTR.O) fell 10 percent after the retailer said it will post third-quarter sales at the lower end of its earlier forecast because of cautious consumer spending and higher gas prices.
Dollar Tree shares, which have fallen more than 11 percent in the last three months, fell to a two-month low of $42.51.
Shares of rivals Family Dollar Stores Inc FDO.N and Dollar General Corp (DG.N) also fell.
Discount stores generally perform well during a downturn as consumers become increasingly picky with their purchases.
Dollar Tree, which sells items for $1 or less at its namesake chain, had earlier forecast sales of between $1.71 billion and $1.75 billion.
The company also attributed the weak forecast to a calendar year shift as two days of pre-Halloween sales will move into the fourth quarter.
Dollar Tree shares were down more than 7 percent at $43.53 on Thursday afternoon on the Nasdaq.
Family Dollar shares were down more than 2 percent at $66.43, while those of Dollar General were down nearly 2 percent at $49.48 on the New York Stock Exchange.
(Reporting by Arpita Mukherjee in Bangalore; Editing by Sriraj Kalluvila)