Signet Jewelers Ltd. SIG stock is up nearly 20% over the past month, driven in part by Taylor Swift's engagement to Travis Kelce and by the company's second-quarter financial results. SIG stock is up 84% over the last six months. See the chart here. Here's a look at these recent catalysts. Signet CEO on the “Taylor Swift Effect”Signet’s CEO J.K. Symancyk joined CNBC's Jim Cramer on Tuesday night to discuss the impact Swift’s engagement had on the jewelry sector. Read Next: Google Stock Roars Back After ‘Gov ...