 Shares of Workhorse Group Inc. WKHS, -10.74 tumbled 10.0 in morning trading Tuesday, after the electric vehicle maker reported second-quarter results that missed expectations, as vehicle sales fell, and lowered its full-year outlook. The net loss narrowed to 21.2 million, or 13 cents a share, from 43.6 million, or 35 cents a share, in the year-ago period. 