Good news on the economic front sent the S&P 500 Index (^GSPC 1.02%) to an all-time high, driven by both impressive corporate earnings and a sharp fall in jobless claims last week. By the end of the day, the S&P had added eight points, or 0.5%, to close at 1,689. But the three biggest disappointments in the index today all posted huge declines for a variety of reasons, none of which impressed shareholders. 

Chemicals and paint giant Sherwin-Williams (SHW 0.54%) cratered 8.3% today after the Mexican government denied the company's attempt to acquire Consorcio Comex of Mexico. In addition to the rejection of the $2.34 billion pickup, first announced last November, Sherwin-Williams also underwhelmed the markets with its disappointing third-quarter forecast.

Weak forecasts were also the bane of eBay (EBAY 1.32%) investors Thursday, as shares plummeted 6.7% lower. Unfortunately, the international markets that eBay has tried to focus its attention on to help stimulate growth in recent years aren't looking as robust as they once did. It's not that sales are worse than they were a year or two ago; it's that sales growth abroad is slowing, lowering expectations for future profitability. Revenue this year is now expected to be at the lower end of 2013 guidance.

Tesoro (ANDV), which won't present investors with the opportunity to be disappointed until August 1, slumped 3.8% today. The oil refiner also fell big time on Tuesday after its peer, Marathon Petroleum, gave its investors a heads-up that second-quarter financial results weren't going to be quite as peachy as expected. The announcement sparked fears that Marathon's warning would translate to a difficult quarter for Tesoro, as well. Keeping in mind that Tesoro's shares are more than twice as volatile as the larger market, today's 3.8% losses look more like a commonplace occurrence than a fundamental setback.