Why Micron Technology, Insteel Industries, and SINA Jumped Today

On Thursday, with the prospect of a holiday-shortened week, the stock market was fairly quiet, with major-market benchmarks sticking close to the unchanged level. A large number of prominent companies tried to cram their earnings releases into the four-day week, and that resulted in widely disparate snapshots of the business climate from many different points of view. For Micron Technology (MU +4.02%), Insteel Industries (IIIN 0.48%), and SINA (SINA +0.00%), though, Thursday was a day of strong gains on good news for their respective stocks.

Source: Micron Technology.

Micron Technology rose 6% after rival memory-maker SanDisk (NASDAQ: SNDK) announced its most recent earnings results. SanDisk's strong performance included sales gains of 13% that drove earnings higher by 63%, as high demand for solid-state drives showed the importance of advanced memory products in powering the smartphones, tablets, and other mobile devices that increasingly rely on the most current technology available. Even as SanDisk gave positive guidance for the current quarter, investors in Micron Technology believed the same factors that have pushed SanDisk's prospects higher should also give Micron the same boost. With so much opportunity for growth internationally, flash-memory-based products have almost unlimited upside, and Micron is arguably just as well-poised to take advantage of that as SanDisk.

Insteel Industries soared 17% as the maker of steel rebar products to secure concrete for construction projects said that sales rose more than 10% in its fiscal second quarter compared to year-ago levels. Although average prices fell slightly, shipment volume gains more than made up for the decline, and Insteel said a fire that had affected part of a Tennessee manufacturing facility didn't hurt the company's overall results. Insteel was also optimistic about the remainder of the fiscal year, as the seasonally strong spring and summer months should lead to increased demand, especially after the brutal winter that halted many construction projects dead in their tracks.

SINA gained 7% after the IPO of its Weibo microblogging service went better than some had expected. Although SINA eventually chose to price the initial public offering at the low end of its expected range, Weibo shares got a nice spike upward, climbing almost 20% above the $17 IPO price. At first glance, that might sound like a disastrous result for SINA, but with the IPO involving less than a 10% stake in Weibo, SINA still retained most of its stake in the microblogging service and will therefore benefit directly from any further appreciation in Weibo's share price. Even after the IPO, SINA also has commanding 80% voting power, allowing it to dictate Weibo's future going forward.