Monday marked a quiet start to the week on Wall Street, and major benchmarks finished close to where they started the day. Market participants appeared content to tread water as they waited for geopolitical happenings to play out later this week, including the potentially contentious U.K. election on Thursday. Comments from the White House about the privatization of the U.S. air traffic control system dominated the headlines, but most of the big moves in the market came from company-specific news. Navistar International (NYSE:NAV), Loxo Oncology (NASDAQ:LOXO), and Helix Energy Solutions (NYSE:HLX) were among the best performers on the day. Below, we'll look more closely at these stocks to tell you why they did so well.

Navistar gets some optimism

Shares of Navistar International climbed 13% after getting favorable comments from an analyst company. Analysts at Baird upgraded the truck manufacturer from neutral to outperform and inched their price target on the stock higher by 3% to $33 per share. Navistar has been going through a transformational process in recent years, and interest from vehicle giant Volkswagen led to an alliance that raised hopes for an eventual full takeover or at least an extensive collaboration that would bolster the truck company's prospects. Even though some investors worry about sluggish conditions persisting, others believe that a rebound in the second half of 2017 could start the cyclical industry back on the upswing. If that's the case, then investors today are getting a jump on what could be a extended move higher for Navistar.

Truck on a bridge in traffic.

Image source: Navistar International.

Loxo gives investors promising data

Loxo Oncology stock soared more than 40% in the wake of the release of interim data from clinical trials of the company's lead drug, larotrectinib. The drug, which won designation from the U.S. Food and Drug Administration as a breakthrough therapy last year, showed promising response rates in phase 1 and 2 trials involving patients with several different types of cancers that shared a certain type of mutation resulting in tumor growth. In particular, the rates of response were somewhat better than treatments that have already won full approval from the FDA, and investors immediately got their hopes up that Loxo would eventually enjoy the same success. Larotrectinib still has a long road ahead of it, but with an accelerated process that could lead to an FDA submission for approval by late this year or early next, Loxo shareholders are hoping that their best wishes will come true.

Helix gets an energy boost

Finally, shares of Helix Energy Solutions jumped 12%. The offshore oil services specialist received favorable comments from analysts at Cowen, who said that they were encouraged by Helix's success in getting a contract for one of its vessels and doing a secondary share offering earlier this year. Helix has come a long way so far this year, working like many of its peers to brace itself against tough conditions in the oil patch in general and in the offshore energy industry in particular. So far, Helix has fared better than some oil-field services companies by focusing its efforts on key maintenance activity that nearly every oil and gas exploration and production company is likely to keep doing. Recent oil price movements haven't been encouraging, but Helix still seems to be following a solid strategy in pursuit of better times ahead.