Chemical merger: Dow Chemical and DuPont shares dropped Friday after rising earlier in the week as the chemical giants confirmed their widely anticipated $130 billion merger. The new company is due to split into three parts, one focused on materials, one on agriculture and the last on specialty products. Dow fell 3 percent, to $53.37, while DuPont declined 6 percent, to $70.44.

 

Chipotle tumble: Chipotle Mexican Grill dropped 3 percent, to $544.90, on Monday in reaction to a warning from the restaurant chain that an outbreak of E. coli linked to its restaurants sent sales plummeting by as much as 22 percent in recent weeks. Its shares closed the week at $565.00.

 

Coffee jolt: Keurig Green Mountain shares soared 74 percent to $90.02 Monday after the company announced it agreed to be acquired by a JAB Holding Co.-led investor group for about $13.9 billion in cash. The stock closed Friday at $88.96.

Commodities fallout: Shares in the mining firm Anglo American plunged by more than 5 percent Tuesday, to $4.91, after it said it would shed around 85,000 employees — or 63 percent of its workforce — amid a radical restructuring program meant to cope with the tumble in commodities prices. Anglo shares closed the week at $4.55.

 

Earnings miss: Costco fell 4 percent, to $161.69, Wednesday after reporting weaker earnings than analysts were expecting, hampered in part by membership fees that grew at the slowest rate in several quarters. Costco shares closed Friday at $160.02.

 

Rumpled: Men’s Warehouse plunged 23 percent, to $14.11, Thursday after reporting earnings per share that were half what financial analysts expected as sales dropped 15 percent at its Jos. A. Bank locations. Its shares closed the week at $14.81.