Which stocks claim the highest growth rates in the entire market? The answer depends on how you define growth.

There are several kinds of growth -- sales, earnings, stock price, cash flow, and more. Growth also requires a definition of time frame. The highest growth stocks over the past 100 years, for example, would be a much different list than the highest growth stocks over the past one year.

To find which are the highest-growth stocks, I chose to use earnings growth for a couple of reasons. First, it tends to drive stock price and cash flow. Second, a stock could have nice revenue growth but still lose money. On that note, I also excluded any stocks for companies that aren't profitable. And instead of using just one time period, I looked at stocks that had strong earnings growth this year and that also are projected to have strong earnings growth over the next year and next five years. After all, the future is more important to investors than the past.

There were eight stocks that met all of these criteria with at least 50% earnings growth this year and at least that level projected for the next year and next five years. The top three of those stocks with the highest projected five-year earnings growth were Netflix (NASDAQ:NFLX), Corcept Therapeutics (NASDAQ:CORT), and Vertex Pharmaceuticals (NASDAQ:VRTX). Here's why these are the highest-growth stocks in the market today.

Businessman pointing to lighted line chart going up

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Netflix

Netflix ranks at the top of the list because of its phenomenal growth in subscribers, which is driving earnings higher and higher. The video-streaming company grew from zero to over 50 million streaming households in the U.S. in just 10 years. Netflix is expected to generate annual earnings-per-share growth of more than 77% over the next five years.

There are two keys for Netflix to achieve this impressive level of growth in the future. First, the company must continue to attract more subscribers. Netflix thinks there could be 10 million to 40 million more subscribers in the U.S. that it can win. The great opportunity is in international markets, though.

Netflix's second key to success is to pull off this growth at a lower cost per subscriber. One way the company plans to do so is by producing more original content. While Netflix spends more upfront on its original shows, it makes more money over the long run because there isn't another production company taking its cut. Original content is also helping Netflix attract the important millennial demographic group.

Netflix menu featuring "Stranger Things" at top

Image source: Netflix. 

Investors will have to pay a hefty price tag because of Netflix's growth, though. Shares currently trade at a whopping 93 times expected earnings.

Corcept Therapeutics

Corcept Therapeutics beats Netflix in earnings growth this year and projections for next year. However, the biotech narrowly comes in second over a longer time frame, with Wall Street projecting five-year annual earnings-per-share growth of 73%.

Cushing's syndrome drug Korlym has fueled Corcept's growth. Around 20,000 Americans have Cushing's syndrome, which is caused by prolonged high levels of the hormone cortisol. Another 3,000 new patients are diagnosed with the condition each year, and there are a large number who suffer from Cushing's syndrome but go undiagnosed.

While continued sales momentum for Korlym should continue to be the primary source for Corcept's earnings growth, the biotech does have another pipeline candidate in clinical testing as well as a couple of pre-clinical programs. CORT125134, which is being evaluated in two phase 2 clinical studies, holds the potential to be an even bigger success than Korlym, because it could provide similar benefits as Korlym without some of the side effects.

With its tremendous growth potential, it's probably not too late for investors to buy Corcept stock even though it's up more than 140% so far this year. And despite shares trading at 25 times expected earnings, the strong growth prospects actually make Corcept a bargain buy.

Scientists looking at image of DNA strand

Image source: Getty Images.

Vertex Pharmaceuticals

Vertex Pharmaceuticals isn't too far behind Corcept, with projected five-year annual earnings-per-share growth of 68%. The biotech could post the highest earnings growth of all three stocks next year, however, thanks to its successful cystic fibrosis (CF) franchise.

Both the short-term and long-term prospects for Vertex look great. Over the short term, the biotech should benefit as it finalizes additional reimbursement deals for CF drug Orkambi in Europe. Vertex also hopes to receive an additional approval in Europe for Orkambi in treating patients between the ages of six and 11.

Over the long term, Vertex's opportunities are even better. The company anticipates U.S. approval of a combination of tezecaftor and Kalydeco by Feb. 28, 2018. Vertex is evaluating several triple-drug combos that the company thinks will ultimately enable it to reach 90% of all CF patients.

Vertex stock looks expensive at first glance, with shares trading at nearly 49 times expected earnings. However, its growth opportunities make the biotech stock much more attractively valued.

Keith Speights has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Netflix. The Motley Fool recommends Vertex Pharmaceuticals. The Motley Fool has a disclosure policy.