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What happened 

Shares of jeweler Tiffany & Co. (NYSE:TIF) jumped 12.3% in November, according to data provided by S&P Global Market Intelligence , as a buyout and an analyst upgrade had investors cheering on the stock. 

So what 

Diamond-selling competitor Blue Nile (NASDAQ:NILE) agreed to a $500 million buyout offer, paying investors $40.75 per share in cash. The deal coincided with a sharp move higher for Tiffany stock on speculation the company could consider a buyout. The upward momentum continued as analysts at Cowen increased their rating on the stock from market perform to outperform and added a $90 price target. 

Interestingly, third-quarter earnings released late in the month didn't elicit much of a reaction from the market. Sales rose 1% in the quarter and fell 2% on a same-store basis, hurt by a 7% decline in comparable sales in Asia-Pacific. On the bottom line, net income rose 4.5% to $95.1, or $0.76 per share. 

Now what 

The move higher for Tiffany stock in November was largely speculative after the Blue Nile deal and analyst upgrade. But the earnings report was more important long term. Investors should like that results are improving slightly after a fairly tough year in 2015. Shares are still expensive at 23 times earnings, but that didn't scare off investors last month as the stock moved higher.