Stocks have done extremely well over the past year, extending the eight-year-old bull market and thriving on strong sentiment from investors. The favorable conditions in the stock market have led to a greater number of stocks posting gains of 100% or more since July 2016, and among these winners, you'll find some of the best-known companies. Read on to find out how II-VI (COHR -3.60%), iRobot (IRBT -4.79%), and Netflix (NFLX -0.04%) have done so well and what lies ahead for the stocks looking forward.

IIVI Chart

IIVI data by YCharts.

II-VI stays laser-focused

The laser industry has been red-hot lately, and customers in many different industries have sought to find ways to take advantage of advances in laser technology to make their own operations more efficient. As a producer of lasers and related components, II-VI has jumped at the opportunity to expand its business, and spending on research and development has paid off with higher sales and more profitable margins.

II-VI sees a lot of potential in its products, including the recent release of a new line of fiber laser products and updates to laser diodes used in cutting and welding applications. The laser maker sees high demand for many of its product lines, and as the industrial economy continues to strengthen, the prospects for even faster growth should become available. II-VI has competitors in the laser business, but it has done a good job of staking its claim during the best of times for the industry as a whole.

Roomba vacuum cleaner.

Image source: iRobot.

iRobot vacuums up profits

Consumers know iRobot for its Roomba vacuum cleaner, which maps out a room and navigates furniture and other obstacles automatically. The company has built on the success of the Roomba, offering other products like the Braava hardwood cleaning tool. With the opportunity to earn strong profits from the consumer end of the business, iRobot made the strategic decision to sell off non-core applications, which primarily included military robotic products it sold to the U.S. Department of Defense.

iRobot has become extremely popular in the U.S., but it's also expanding its scope across the globe. Having become the dominant brand in Europe and Asia as well as domestically, iRobot has built up a solid foundation of fundamental strength. As applications for consumer robots expand, iRobot is in the perfect position to identify preferences among those who buy its products and keep innovating to meet customer needs for years to come.

Netflix shows a great picture

Netflix has become the giant in the video streaming business, offering its subscription services to viewers in many areas around the world. Growth for the company has only accelerated recently, with Netflix adding 2 million more subscribers than even it had expected during the second quarter of 2017. Having gone beyond simply licensing other companies' content for streaming, Netflix has invested heavily in building out its own in-house studio for content creation, and the result has been critically acclaimed shows that have captured audience members and resulted in greater demand for the service.

Netflix still has a long path ahead of it in order to maximize its potential. Even though it has done a good job of building out its home service in the U.S., Netflix wants to move forward aggressively internationally to span the globe before competing companies gain a bigger foothold in their home markets. Adapting the service to cater to mobile users will also be a key priority, especially because in many emerging countries, wireline connections will never be available and wireless communications will be the exclusive way that viewers can get content. Netflix has done a good job of identifying what it needs to do going forward, and now it just needs to execute on its strategy to turn its hopes into reality.

It's rare for stocks to double in a single year, but these three companies have a lot going for them. II-VI and iRobot are small enough to have plenty of growth potential ahead, but even though Netflix is markedly larger, its first-mover advantage makes it a solid pick for future success as well.