NEW YORK (TheStreet) -- Shares of Tiffany & Co.  (TIF - Get Report) are down 2.06% to $63.40 in afternoon trading on Tuesday, less than two weeks after the company authorized a three-year $500 million repurchase program.

Under the iconic jeweler's previous share buyback program the company's board authorized a $300 million buyback of which about $61 million remains. The company bought back shares worth $60 million in the third quarter and $116 million in the first three quarters of fiscal 2015.

However, despite the added shareholder value, Tiffany's sales for November and December -- the important holiday months -- were down 3% year over year on a constant currency basis to $961 million. Comps also fell 9% during that period. The company augmented its full fiscal 2015 earnings per-share forecast, now expecting a 10% decline in earnings per share.

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As a result, analysts at Cowen lowered their rating on the company to "market perform" from "outperform" and reduced its price target to $70 from $75. The firm cited uncontrollable risks as a reason for the downgraded outlook while also saying that it prefers the stock of rival Signet Jewelers (SIG).

"We prefer to play the jewelry space through Signet's exposure to the middle-income consumer, as well as their propensity to remain a leader and gain additional share in a fragmented market," analysts said. 

TheStreet identified several strengths in the company, including its impressive record of earnings per share growth, compelling growth in net income and largely solid financial position with reasonable debt levels by most measures. However, as a counter to these strengths, it also found that the stock has had a generally disappointing performance in the past year.

TIF Chart TIF data by YCharts

TheStreet Ratings uses an algorithmic model to determine a rating for risk-adjusted total return prospect over 12 months.