The S&P 500 was up over 11% last year, exceeding many analyst expectations. Despite the bullish market, some companies still underperformed. Sometimes it is the entire industry taking a hit, and other times, the poor performance is specific to an individual company. 

Today, three Motley Fool contributors weigh in on the turnaround stories they're watching for 2015: Coach (NYSE:TPR),  Advanced Micro Devices (NASDAQ:AMD), and InvenSense (NYSE:INVN).

Andres Cardenal (Coach): Coach made a series of expensive mistakes over the last several years -- the company expanded too quickly, designs did not resonate well among consumers, and excessive promotions eroded the brand image. However, management is actively trying to turn things around, and Coach is an interesting candidate to watch in 2015 and beyond.

The company is reducing its store count and cutting back on promotions in order to recover its aspirational halo. It also hired Stuart Vevers as the new creative director in September 2013, and he is working to transform Coach into a full lifestyle brand.

The December quarter will be the first full quarter including sales from his new collection. Considering the importance of the holiday shopping season, the next earnings report should give investors an opportunity to evaluate Coach's ability to get back on track.

Also, while total sales in North America declined 19% year-over-year to $634 million during the third quarter, international revenues were up 4% to $381 million. Sales in China, a particularly promising market for the company, jumped 10% during the period, so international markets seem to offer considerable room for growth in the mid-term.

For what it's worth, management believes the new collection is performing according to expectations, and CEO Victor Luis said in the last conference call that press coverage for this new collection was "overwhelmingly positive, building on the response to Fall 2014 and driving fashion, credibility, and buzz."

Anders Bylund (Advanced Micro Devices): AMD had a terrible year in 2014. Share prices plunged 32% lower, mostly in a difficult span from September through October. The microchip designer missed Wall Street earnings targets in each of it two latest quarters, and analysts expect more pain ahead.

AMD CEO Lisa Su. Source: AMD

But the plucky semiconductor underdog is under new management, and I think that recently appointed CEO Lisa Su has what it takes to turn the beat around. The market, on the other hand, begs to differ.

The biggest drop in October had nothing to do with soft earnings but sprung from the news that Su would be replacing Rory Read in the corner office. The market reaction was like a huge vote of no confidence in the new CEO.

I'm here to tell you that Su knows the business inside and out, having run AMD's global (read: international) business unit since 2012. She comes with a rock-solid technical pedigree with an MIT doctorate in electrical engineering. She's spent more than 20 years running technical and leadership operations at the chip divisions at FreescaleIBM, and Texas Instruments. She's a much needed tech-oriented upgrade from Read's deeper business-side focus.

Rory Read started pointing AMD in a new direction. Su continues to move the company out of the commodity PC processor market and deeper into custom products for markets like gaming consoles and the Internet of Things.

Lisa Su is the right person with the right strategy, at exactly the right time. If the market understands these things in 2015, AMD's stock should run higher once again.

Ashraf Eassa (InvenSense): Over the last year, shares of MEMS vendor InvenSense have lost about 35% -- pretty rough for a company that just won a spot in the latest Apple iPhones!

Last quarter, the company saw a large drop in gross profit margins as a result of an (unexpected) inventory write down. I believe this shook investor confidence, particularly as poor inventory management lies squarely on the shoulders of the people running the company.

InvenSense also reported margin pressure as a result of high customer concentration at Apple and Samsung, which stoked the fears of the risks typically associated with this issue -- continued margin pressure and the potentially huge financial impact of losing a major customer. 

As I've indicated previously, I think the InvenSense "turnaround" story in 2015 will consist of two parts. First, InvenSense needs to avoid the execution mishaps that it suffered in 2014. The company really can't afford any negative surprises in the near future if it wants to restore investor confidence. Things happen and no company will execute 100% each-and-every quarter, but InvenSense needs to take particular care in the near-term to set expectations properly and execute well on those expectations.

Next, the company needs to prove that it can, without further eroding its gross profit margin profile, keep its premium mobile device wins while at the same time delivering on its stated goal to push more into the midrange phone market. This could be demonstrated by growing the business at a rapid clip over the next year or so, while maintaining at least a 45% gross profit margin.

InvenSense reports its quarterly earnings on Jan. 29th, and I look forward to seeing how the company performed relative to guidance and what it ends up guiding to for the following quarter.