The stock market has been extremely volatile lately, with alternating bouts of euphoria and despair whipsawing major-market benchmarks. On Wednesday, bullish investors won the battle, as the Dow and S&P both posted gains of about 1% on the heels of a generally positive start to earnings season. Yet for investors in Linear Technology (LLTC), ADTRAN (ADTN), and ASML Holding (ASML -1.62%), the news wasn't nearly as good, and the stocks were among the worst performers on an upbeat day for the market as a whole.

Linear Technology fell more than 4% after the maker of analog semiconductor chips issued its fiscal third-quarter earnings report last night. Even though Linear Technology's revenues rose 11% from the year-ago quarter, investors had hoped for slightly better sales growth, and guidance for revenue for the current quarter fell in a range whose midpoint was somewhat below expectations as well. The key to Linear Technology's future results could be whether the automotive and communications sectors do well, as the chipmaker relies on those markets in particular for much of its sales. Even though an improving economy has lifted prospects for companies in the chip sector, competition could pose threats to Linear Technology's long-term growth.

Source: ADTRAN.

ADTRAN dropped 9% following its own earnings report last night, in which the communications-equipment manufacturer disappointed investors with just a 2.8% rise in revenue. Even though ADTRAN saw a 56% jump in international sales, poor results domestically held back the company's overall sales figures, and even better-than-expected earnings that resulted in part from rising gross margins worldwide weren't enough to bolster investor confidence in ADTRAN. Moreover, with guidance suggesting that those margin levels could fall in the second quarter, shareholders are nervous about whether ADTRAN's results could point to further difficulties for telecom equipment makers more broadly.

Elsewhere in the chip world, ASML Holding declined nearly 3.5% after beating earnings expectations for the first quarter but giving poor revenue guidance for the current quarter. Sales for the maker of semiconductor equipment soared from year-ago levels, as a rebound in the memory market drove demand. But ASML Holding said that second-quarter sales would be hurt, cutting its overall guidance for the first half of 2014. The news sent other stocks in the semiconductor-equipment sector falling as well, and given how technology has been in the spotlight lately, declines could point to further troubles ahead in the sector.