Money has been growing on trees for the dollar store chain lately, but there still remain risks to keep an eye on.
Dollar Tree (DLTR -0.74%) stock is up more than 20% over the last three months. Although much of the gain can be attributed to acquisition activity, its latest quarterly earnings report shows why it's moved 35% higher from the lows hit in February: same store sales recorded their best gain in three years as customers continue to respond to the growing assortment of consumers products that offer a compelling value proposition.

Fuel prices have plunged and are expected to stay low, but another spike could always cause a shock to the system. Photo: Flickr via Richard Masoner

A trucker's strike and a slowdown by longshoremen on the West Coast is raising costs and risks for retailers everywhere. Photo: Flickr via tdlucas5000

Two steps back, one step forward if Dollar Tree successfully acquires Family Dollar. Photo: Flickr via Mike Mozart