 Shake Shack Inc.s SHAK, -4.26 stock climbed 5.9 Thursday before market open, lifted by a narrowing third-quarter loss and revenue that just topped analysts estimate. The restaurant chain reported a third-quarter loss of 2 million, or 5 cents a share, compared with a loss of 2.2 million, or 6 cents a share, in the same period last year. 