The stock market fell on Friday, giving back a portion of its gains from earlier in the week. Poor performance in the energy sector continues to cause concern among investors, outweighing even the positive impact from more investor-friendly monetary policy from the Federal Reserve earlier this week than some had expected.

Major market benchmarks fell about half a percent, but several stocks suffered even greater declines. Among them were Salesforce (CRM -2.15%), Houghton Mifflin Harcourt (HMHC), and Devon Energy (DVN -0.93%).

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Salesforce keeps quiet about a possible Twitter buy

Salesforce dropped 6% in the wake of reports that the customer relationship-management specialist might be among those companies interested in buying social-media giant Twitter. Investors in Salesforce have already had to deal with the challenges the company has faced in integrating past acquisitions, and even though Twitter currently comes at a relatively low price, it would still represent a big commitment of money and effort to bring it under the Salesforce corporate umbrella. Reports suggest that any talks that might be occurring are at early stages at the moment, but investors appear to be expressing their displeasure at the idea of a deal.

Houghton sees its chief leave

Houghton Mifflin Harcourt fell 11% after its CEO resigned late Thursday. Linda Zecher said that she would leave the publisher following the company's warning that billings would likely finish the year at the lower end of its previously revised guidance.

Taking Zecher's place will be Gordon Crovitz, who has been on the Houghton board since 2012 and is a former publisher of The Wall Street Journal. Crovitz will play an interim role as the company searches for a permanent chief executive. With all the challenges facing the industry, Houghton will have to work hard to establish itself as the go-to company for global learning and educational content.

Devon Energy slumps

Finally, Devon Energy fell 6%. Commodities generally had a poor day on Wall Street, with crude oil falling sharply, and the VanEck Vectors Gold Miners ETF (GDX 0.74%) losing almost 3% on Friday. OPEC will meet to discuss the future direction of the oil market, and market participants fear that the countries in the cartel will be unable to reverse the weak price performance in energy over the past year-and-a-half.

Devon has already sold off assets in order to help fund an anticipated pick-up in capital expenditures to increase production for 2017. If oil prices don't manage to recover much beyond their recent range between $40 and $50 per barrel, then Devon's hopes to profit from higher production won't work out as well as it currently expects.