Image source: Petroleo Brasileiro.

Monday's stock market movements showed the same lack of resolve that investors saw last week. Major market benchmarks spent most of their day in positive territory, but toward the end of the afternoon, they retreated into negative territory. Market commentators once again looked at the macroeconomic implications of a potential Federal Reserve interest rate increase as soon as next month, but that vague and overarching justification for stock movements is likely to hide more volatile movements in certain subsectors of the market between now and the next Federal Open Market Committee meeting in late June. Several stocks fell sharply on Monday, and among the biggest movers to the downside were Petroleo Brasileiro (NYSE:PBR), Lands' End (NASDAQ:LE), and Tribune Publishing (NYSE: TPUB).

Petroleo Brasileiro finished the day down 5% as the ongoing controversy over the Brazilian oil giant continued to develop. The latest news includes reports that unions representing oil workers for the company aren't happy with the selection of Pedro Parente as the new president of Petrobras, arguing that he favors privatizing certain aspects of the company and will therefore work against the interest of employees. Petrobras is tough for investors to understand fully, because the Brazilian government retains considerable control over the enterprise. As a result, Petrobras doesn't always act in its shareholders' best interest, and even if the energy markets continue to recover from their worst levels of the year, there's no guarantee that the return to more normal conditions will result in financial gains for company shareholders.

Lands' End fell 6% after announcing late last week that Chief Marketing Officer Steven Rado had resigned effective Saturday. The retailer said that it intends to do an external search to replace Rado, who had served in the position at Lands' End for about two years. The move is the second high-profile departure from the company in 2016, following the replacement of CFO and COO Michael Rosera with former RadioShack executive James Gooch. The company has struggled in a tough overall retail environment, and the loss of confidence within Lands' End's C-suite is mirrored in the share-price performance of its stock over the past year and a half.

Finally, Tribune Publishing plunged 15%. The publishing company rejected the latest offer from rival Gannett, and for its part, Gannett said that it could decide to withdraw its bid if Tribune doesn't change its mind and accept it. However, Tribune sold a 13% stake in itself to billionaire investor Patrick Soon-Shiong and his Nant Capital investment vehicle, offering 4.7 million shares at $15 per share for a net total of $70.5 million. With Soon-Shiong taking a seat on Tribune's board as vice chairman, it's looking increasingly unlikely that a merger deal will go through as Gannett had initially hoped.