Going into the weekend, investors were willing to dismiss the failure of Cypriot lawmakers to come to a final conclusion about its bailout plans, bidding stocks higher. The S&P 500 (SNPINDEX:^GSPC) finished near the highs of the day, rising 11 points, to 1,557, just eight points below its all-time record high.

Among the 500 stocks in the large-cap index, the technology sector was well-represented. Advanced Micro Devices (NASDAQ:AMD) was the biggest loser of the day, declining by almost 4%, and following up on yesterday's similar 4% decline. Having perennially lagged behind Intel (NASDAQ:INTC) in the PC microprocessor industry, AMD had its chance to outshine its rival by moving more quickly to capture opportunities in the mobile-device arena. Yet it hasn't done any better of a job getting into mobile than Intel has and, as new competition strengthens, AMD risks fading into insignificance.

Monster Beverage (NASDAQ:MNST) fell 3.7%. Late yesterday, a study presented at a meeting of the American Heart Association suggested a possible connection between energy drinks to higher blood pressure and potential heart-rhythm problems. With some already having blamed energy drinks for deaths and illnesses, the study could threaten the long-term viability of Monster Beverage's business model if its conclusions prove to be true.

Finally, F5 Networks (NASDAQ:FFIV) rounded out the three worst stocks list, dropping about 2.25%. Oracle's earnings miss earlier this week threw the entire networking sector into turmoil, as it called into question the general strategy of trying to go beyond niche specialties to provide broad one-stop solutions for IT customers. An analyst's downgrade yesterday of router and networking rivals Cisco Systems and Juniper Networks didn't help F5 either, as conditions across the industry appear to be in danger of worsening in the near future.

Fool contributor Dan Caplinger has no position in any stocks mentioned. You can follow him on Twitter @DanCaplinger. The Motley Fool recommends Cisco Systems, F5 Networks, Intel, and Monster Beverage. The Motley Fool owns shares of F5 Networks, Intel, Monster Beverage, and Oracle. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.