The bull market is more than 8 years old, and those who invested at the March 2009 lows have more than tripled their money. Yet some stocks have managed to deliver strong gains in a much shorter time frame. In particular, Tivity Health (NASDAQ:TVTY), Shopify (NYSE:SHOP), and Ultra Clean Holdings (NASDAQ:UCTT) have tripled in value in just the past 12 months. Smart investors want to know whether there are more gains in store for these three high-flying companies, and below, you'll get some details on how those stocks got to where they are today and what lies ahead for them.

TVTY Chart

TVTY data by YCharts.

Tivity capitalizes on demographic shifts

The population of older Americans has been on the rise as the baby boom generation enters retirement. That has opened up new opportunities for businesses, and Tivity Health, which was formerly known as Healthways, has aimed to take full advantage of aging demographics by restructuring to emphasize key growth initiatives. In particular, the Silver Sneakers, Prime Fitness, and Physical Medicine businesses are all expected to be growth drivers, and investors got excited early on that the restructuring would go well.

More recently, Tivity has seen its efforts pay off in stronger financial results and more favorable guidance, and the company is more optimistic than ever that its business could get a boost from proposed healthcare reform. With population demographics remaining favorable for years to come, Tivity could continue to see advances well into the future.

Healthways logo.

Tivity was formerly known as Healthways. Image source: Tivity Health.

Shopify profits from the e-commerce gold rush

New entrepreneurs now realize that e-commerce is a great way to get exposure for their products without having to go to the expense of establishing a physical storefront, and there's been a rush to set up a strong online presence among those seeking to sell their wares. Shopify offers tools to make e-commerce easier for entrepreneurs, and the internet equivalent of selling picks and shovels to gold prospectors has worked well so far for the newly public company.

Shopify isn't profitable yet, but key metrics such as revenue, gross merchandise volume, and platform payments have exhibited impressive growth trajectories. As e-commerce becomes increasingly competitive, users will look to Shopify to make getting into the business simpler and more efficient. If that trend takes hold, it won't be long before Shopify gets out of the red and starts making money for shareholders.

Ultra Clean makes technology easier

Finally, Ultra Clean Holdings has seen the strongest returns among these three stocks. In fact, Ultra Clean had actually had even better performance until recently, falling back from having been up more than 350% at one point. The specialist in subsystems and turnkey semiconductor equipment solutions has benefited greatly from an upsurge in the cyclical health of the chip business, and Ultra Clean in particular chose to move beyond gas-panel products to capture a broader piece of the strengthening sector.

The semiconductor business is cyclical, and so it's entirely possible that Ultra Clean could give back a portion of its gains if the chip sector heads south. Nevertheless, Ultra Clean has done a good job of distinguishing itself in a competitive industry, and that should bode well for its long-term prospects.

It's rare for a stock to climb more than 200% in just 12 months, and no investor should expect a stock that has already tripled to deliver a repeat performance over the year to come. But even if the pace of their returns moderates somewhat going forward, all three of these stocks have solid business fundamentals underlying their past success, and favorable conditions could keep the good times rolling throughout 2017 and beyond.

Dan Caplinger has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Shopify. The Motley Fool has a disclosure policy.