Stocks rebounded from yesterday's stumble today, advancing on Federal Reserve Chairwoman Janet Yellen's firm but vague vows to keep interest rates at historical lows. How was she firm, yet vague, simultaneously? She was unwavering in her conviction that rates should remain low, but absolutely noncommittal when pressed on how long those policies should continue. Though she caught some flak for being evasive, monetary policy would cease to be effective if it were precisely choreographed ages in advance. Though Wall Street received Yellen's remarks well, it cringed at the sight of Whole Foods Market (NASDAQ:WFM), Yahoo! (NASDAQ: YHOO), and First Solar (NASDAQ:FSLR) today, and each stock finished near the bottom of the S&P 500 Index (SNPINDEX:^GSPC). The S&P, for its part, added 10 points, or 0.6%, to end at 1,878.

Whole Foods Market was far and away the most abject laggard in the index, plunging 18.8% after its quarterly report. Both sales and net income in the period came in below expectations, and to compound the pain, the grocer also cut its earnings forecast for the year! Not only is the writing on the wall in terms of Whole Foods' same-store sales slowdown, but CEO John Mackey's candid views about the competitive environment were also revealing. Saying that the company's niche had "gone mainstream," and that rivals doing "what we're doing" were springing up left and right, it's tough to see the business' long-term competitive advantage. 

Shares of Yahoo! stumbled 6.6% on Wednesday, even as investors digested news of a windfall in the form of Chinese e-commerce giant Alibaba's IPO plans. Yahoo! did investors the service of a lifetime in 2005 when it snatched up 40% of the Emerging Alibaba Group for $1 billion in 2005. Since then Alibaba has grown explosively, and Yahoo!'s stake, even after taking some eye-popping gains along the way, is worth an estimated $26 billion. With Alibaba announcing plans to go public sometime this fall, Yahoo! will be forced to sell about 40% of its stake, putting the onus on the search company to generate growth of its own with the new funds.

Source: First Solar website

I expect that the endless quarter-to-quarter management of Wall Street expectations has grayed more than one executive's mane. But sometimes the inanity of the market's short-term focus can make you, the bystander, want to rip your hair from its roots -- an uncomfortable emotion that I myself experienced upon glimpsing First Solar's slide today. While First Solar is a market leader in the rapidly emerging field of solar power panels; and while the stock trades at a reasonable multiple; and while the company nearly doubled first quarter earnings forecasts, second quarter earnings projections weren't up to snuff for Wall Street. As a result, First Solar stock shed 5.8% Wednesday, even though the company increased its full-year EPS, operating income, and cash flow guidance. The good news: ardent believers in the company's long-term success can always take the contrarian view -- and tell Mr. Market to shove it where the sun don't shine.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.