Luminar's Q3 sales came in way below Wall Street's expectations. So why did the stock rally?Luminar (LAZR 10.78%) stock posted big gains in Tuesday's trading following the publication of the company's latest quarterly results and the announcement of a new deal. The lidar technology specialist's share price closed out the daily session up 10.8% and had been up as much as 15.7% earlier in the day's trading.Luminar published its third-quarter results after the market closed yesterday, reporting sales that came ...