On Tuesday, stock markets went through the roof, with most major-market benchmarks hitting new all-time or multi-year highs on optimism that the second half of the year will enjoy stronger economic growth than the first half did. In the wake of the melt-up, which sent the Dow up triple digits on the day, hundreds of stocks hit new yearly highs. Yet among the more impressive of the gains were those of Southwest Airlines (LUV -1.05%), Baidu (BIDU 0.59%), and Western Digital (WDC -1.19%), which set new highs with more assertive moves.


Source: Southwest Airlines.

Southwest Airlines jumped more than 3% as the airline started offering international service to Caribbean nations for the first time in its long and storied history. Southwest passengers will be able to fly to Jamaica, the Bahamas, and Aruba, and the airline has taken the opportunity to promote its vacation bundles to customers in order to get passengers used to thinking of Southwest as a Caribbean travel option. The move is just the latest in the benefits that Southwest has gotten as it integrates its AirTran acquisition, and Southwest expects to add Mexico and the Dominican Republic later this year.

Baidu rose almost 2.5% as investors anxiously await the initial public offering of Chinese Internet giant Alibaba. Recently, Baidu has seen its market share in the Chinese Internet search arena continue to fall, with latest figures from the first quarter showing that its page-view share dropped below the 60% mark while rival Qihoo 360 jumped above 25%. Yet if Baidu can use its broader array of services, including its greater focus on mobile applications, to its advantage, then Qihoo's challenge could eventually become moot as users gravitate away from PC-based search and toward using mobile devices more prevalently.

Source: Western Digital.

Western Digital gained more than 2% as the maker of hard-disk drives and other storage solutions earned positive comments from stock analysts. In particular, investors see the potential for big gains from both Western Digital and its main hard-disk rival, pointing to the possibility of much higher margins than most investors expect to see. Already, we've seen positive comments throughout the tech space pointing to unexpected gains in PC sales from the need to upgrade unsupported operating-system software. Many of those PCs will have hard-disk drives, helping push sales high and extending the lifespan of Western Digital's hard-disk products. At the same time, Western Digital has seen the need to update its offerings, with efforts to come out with solid-state drives and hybrid drives to provide speed and efficiency to those who can afford to pay for the more expensive storage options.