 Shares of Thor Industries Inc. THO, 2.47 shot up 6.3 in premarket trading Wednesday, after the maker of recreational vehicles reported fiscal second-quarter profit and sales that rose well above expectations, as strong demand for RVs and towables in North America offset continued supply chain challenges. Net income for the quarter to Jan. 31 more than doubled to 266.6 million, or 4.79 a share, from 132.5 million, or 2.38 a share, in the year-ago period. 