The stock market rebounded on Wednesday as investors responded favorably to news that Hong Kong officials would back down from hard-line positions taken against protestors. A big bounce in crude oil prices also helped lift key players in the energy sector. Yet some of the best gainers had special circumstances fueling their moves higher. Navistar International (NYSE:NAV), Michaels Companies (NASDAQ:MIK), and Box (NYSE:BOX) were among the top performers. Here's why they did so well.

Navistar drives higher

Shares of Navistar International climbed 13% after the truck and heavy equipment manufacturer reported favorable fiscal third-quarter financials. Revenue jumped 17% compared to year-earlier levels, with Navistar saying that a big boost to core sales of trucks and buses in the U.S. and Canada contributed the most to its performance. Adjusted net income soared by more than half, and CEO Troy Clarke pointed to increases in market share as further evidence that the company is doing well. Having built up momentum throughout the year, Navistar looks poised to keep benefiting as long as economic activity remains robust in key markets.

Large semitractor-trailer.

Image source: Navistar International.

Michaels stays crafty

Michaels Companies saw its stock pick up 12% following the arts and crafts retailer's second-quarter financial report. Revenue fell 2% year over year on a tepid 0.3% increase in comparable-store sales, but adjusted net income was up 12% from year-ago levels after accounting for the charges associated with the closing of the company's Pat Catan's store locations. However, the stock gave up much larger gains from earlier in the day after comments from CEO Mark Cosby suggested that Michaels remains exposed to Chinese tariffs. With uncertainty over the possibility of yet more trade duties coming into effect later this year, Michaels will have to prepare for whatever happens on that front.

Box attracts activists

Finally, shares of Box rose 12%. The cloud storage company got interest from activist investors at Starboard Value, which disclosed that it had taken a 7.5% equity stake in Box. Starboard didn't go into great detail about its plans for Box, simply saying that it believes that the cloud company isn't fully valued at current prices. Box was equally terse about its anticipated reaction to the news, only saying that it's looking to keep building up its presence in cloud content management. Even after the move, shares essentially haven't done anything since the beginning of 2015, and that could explain why Starboard thinks there's potential upside to taking action.