NEW YORK ( TheStreet) -- Oil-tanker stocks have been a hot commodity of late.Share prices in the so-called "wet" sector of the merchant shipping business have climbed sharply since 2010 dawned two weeks ago. Several short-term factors have prompted the rally. Cold, inclement weather has both lifted demand for heating oil in the Northern Hemisphere and roughened seas, delaying shipments and thus reducing the supply of vessels on the market. In the Bosphorus -- a key oil-transport artery that flows through Istanbul and, with the Dardanelles, links the Black Sea and the Mediterranean -- weather has disrupted transport so much that the ships have stacked up, creating delays of six days in one direction and eight days in the other. Shares of Frontline ( FRO), the biggest of the U.S.-listed tanker companies by market cap, have soared 23% since New Year's Eve, outperforming its peers. Shares of General Maritime ( GMR), meanwhile, have risen 18.7% since Dec. 31, Overseas Shipholding ( OSG) 16%, Ship Financial ( SFL) 15%, Teekay ( TK) 13.7%, and Nordic American Tanker ( NAT) 12.4%. Though the supply-demand balance hasn't tilted out of whack, observers say, the current environment favors the ship-owner rather than the oil company. Why? An owner who decides to play hardball in negotiations with a charterer may lose out on, say $50,000 each day he stalls for a higher rate, explained Mike Reardon, a vice president at Imarex, an Oslo-based maritime derivatives exchange. "But if a charterer misses a ship, he may have to shut down a refinery. The pain is asymmetric." Several investment firms have come out with bullish calls on the tanker business in the last week or so, including Jeffries & Co. and Dahlman Rose (which may prompt other sell-side analysts to make similar statements projecting upward moves in tanker stock prices). This, along with a brightening near-term outlook, may have also caused a short squeeze among shares in the sector, sharpening the recent rally.