Tile Shop Holdings Inc.: The Minneapolis company’s shares lost 36 percent of their value on Monday, closing at $8.45, after Tile Shop Holdings Inc. announced preliminary third-quarter results that did not meet expectations. The company said it expects sales to rise 7 percent to $84 million. Comparable store sales are expected to rise 1 percent, down from a 5.7 percent increase in the same period a year ago. CEO Chris Homeister said the results were affected by new product introductions, increased promotions and advertising and competitive pricing. By Friday, the shares had regained a bit of their value, closing at $8.65.


Delta Airlines Inc.: Delta Airlines Inc.’s shares rose 6.62 percent in afternoon trading on Tuesday after the Atlanta-based carrier reported a softer-than-expected impact from powerful and disruptive hurricanes last month. In its report, Delta lowered its third-quarter operating margin guidance to between 15.5 and 16.5 percent, from between 16.5 and 17.5 percent. On Friday, after the government slapped another tariff on Canadian competitor Bombardier, shares took another slight ride, ending the week at $52.02.


Costco Wholesale: After its shares lost 6 percent of value on Thursday, Costco’s shares lost another 6 percent on Friday, closing at $157.09. The membership-based warehouse retailer on Thursday reported earnings per share of $2.08, up from $1.77 last year and ahead of estimates. Sales were $42.3 billion, up from $36.6 billion last year; same-store sales rose 6.1 percent. Still, some investors worried about membership renewal rates, margins and competition. Costco also said it had rolled out two grocery delivery services this week, a new step in its efforts to fight growing competition from Amazon and Walmart.