The stock market was mostly flat today ahead of a key House vote on the passage of the Republicans' healthcare bill, which was delayed until Friday after GOP lawmakers failed to gather the necessary support. The Dow Jones Industrial Average lost just 5 points, or 0.02%, while other broader market indexes saw similar small declines. But several individual stocks saw much more severe drops, including Zillow Group (NASDAQ:Z) (NASDAQ:ZG), Proofpoint (NASDAQ:PFPT), and Accenture (NYSE:ACN). Read on to see what drove these unusual moves.

Did Zillow break the law?

Shares of online real estate platform company Zillow Group fell 5% after real estate news site Inman highlighted (may require subscription) the possibility that Zillow's mortgages business may have violated mortgage regulations. More specifically, Inman notes that Zillow recently changed the language around lender ads in its co-marketing program, potentially in response to reported Consumer Financial Protection Bureau (CFPB) inquiries to loan officers regarding whether they were buying Zillow leads.

Hand receiving house key with a "Sold" sign in the background.

Image source: Getty Images.

To be fair, Inman also notes that the CFPB "has not issued any guidance in regards to whether participating in Zillow's lender co-marketing program violates [The Real Estate Settlement Procedures Act (RESPA)]." But even if it hasn't, the resulting uncertainty could stem incremental revenue growth provided by Zillow's budding mortgages segment, where revenue climbed 41% year over year last quarter, to $16.5 million.

A note of caution on Proofpoint

Shares of enterprise security software company Proofpoint dropped nearly 7% after Goldman Sachs analyst Gabriela Borges downgraded the stock to sell from neutral. Borges also reduced her per-share price target on Prooft point to $69 from $77. Proofpoint stock closed today at $73.79 per share.

"While we continue to view the company as a best-in-class asset with improving free cash flow," Borges explained, "we believe risk/reward for the stock is skewed negative."

To be sure, shares of Proofpoint are still up nearly 39% over the past year as of this writing following what Borges describes as a "perfect storm" of tailwinds. Revenue in 2016 climbed an impressive 41% year over year, to $265.4 million, while adjusted net income arrived at $16.9 million, or $0.37 per share, swinging from an adjusted net loss of $6.1 million, or $0.15 per share in 2015. But with shares of Proofpoint trading at 80 times this year's expected earnings even after the drop, it's hard to blame Goldman Sachs for taking a step back today.

Accenture's earnings miss

Finally, Accenture stock declined 4.5% today after the global management consulting and professional services company followed a mixed quarterly report with disappointing forward guidance. 

More specifically for Accenture's fiscal second quarter ended Feb. 28, 2017, revenue (before reimbursements) grew 4.7% year over year, to $8.32 billion, and translated to net income of $876.7 million, or $1.33 per diluted share. Analysts, on average, were expecting earnings of just $1.30 per share on slightly higher revenue of $8.34 billion.

Accenture CEO Pierre Nanterme called it a "strong performance." He further noted growth was broad-based, giving credit to "high-growth areas such as digital, cloud and security services -- which now account for more than 45% of total revenues -- as well as our increasingly innovation-led approach to creating cutting-edge solutions for clients."

Looking forward, Accenture now expects full fiscal-year revenue growth to be in the range of 6% to 8% at constant currency, an increase on the bottom end from its previous guidance of 5% to 8% growth. On the bottom line, Accenture also anticipates full-year adjusted earnings per share of $5.70 to $5.87, an increase on the bottom end from its previous range of $5.64 to $5.87. However, Wall Street was anticipating adjusted earnings near the high end of Accenture's new earnings guidance range. 

In the end, that's not to say Accenture's results were terrible. But given its top- and bottom-line guidance shortfalls -- at least relative to investors' expectations -- it's no surprise to see shares falling today.

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.