NEW YORK ( TheStreet) -- Shares of oil tanker companies, which ended trading Thursday mostly lower, have gone on a staggering run over the last two months.Leading the pack has been Frontline ( FRO), the largest publicly traded tanker company by market cap. Its shares have ripped higher by 42% since early February. Shares of Frontline peer Overseas Shipholding ( OSG) have risen in tandem, gaining about 20% over the same period, though it's been a rockier ride for OSG. Shipping stocks in general are high-beta names, following the broader equities markets, but with an order of magnitude more intensity in either direction. With the Dow Jones Industrial Average breaking through 11,000, it's not entirely surprising that tanker stocks have risen to the degree they have. Further, many tanker stocks have heavy short interest, so whenever they experience a strong upside move, the squeeze is on. But the bull run in the sector has both psychological and fundamental underpinnings. Shipping companies that specialize in moving crude across the oceans have benefited from rising rates for their services, buoyed by the recent run in the price of oil. The daily rate for a Very Large Crude Carrier, the biggest type of tanker ships in the world, has averaged about $50,000 a day in 2010. Late last year, some were predicting average rates for 2010 of $28,000 a day. "All the bulls are coming out now," said Mike Reardon, vice president of research and marketing at Imarex, a clearinghouse of freight derivatives. "People were calling for Armageddon, and VLCC owners are out with champagne bottles right now." Wall Street analysts have taken notice. Bears have turned into moderates. Moderates have morphed into bulls. And at least one bearish analyst, Martin Korsvold of the Norwegian investment house Pareto, flipped completely, upgrading the tanker sector last week. He lifted his rating on both Frontline and Overseas Shipholding's stock to buy from sell, writing, "The listed companies in our tanker universe are capitalized to weather choppy seas, hence the risk is on the upside." Naysayers remain, however. And one such investor believes most stocks in the tankers sector are overbought, especially those companies who own no VLCCs, which is to say: every publicly traded tanker outfit except Frontline and Overseas Shipholding.