Image seeing your investment of $10,000 grow to more than $60,000 in just three years. That would be awesome, wouldn't it?

Investors who bought big enough stakes in three stocks in mid-2014 and held on don't have to imagine that scenario. Eagle Pharmaceuticals (NASDAQ:EGRX), Exelixis (NASDAQ:EXEL), and NVIDIA Corporation (NASDAQ:NVDA) achieved returns of more than 500% over the last three years. Here's how they did it.

Man pointing to chart going up

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Eagle Pharmaceuticals

Eagle Pharmaceuticals stock is up more than 530% over the last thee years. It's been a wild ride for the biotech's shareholders, though. There have been some huge swings in the share price along the way.

A key catalyst for Eagle Pharmaceuticals came in February 2015, when the company licensed bendamustine hydrochloride to Israel-based drugmaker Teva (NYSE:TEVA). Eagle and Teva won approval from the U.S. Food and Drug Administration in December 2015 for the drug in treating chronic lymphocytic leukemia (CLL) and indolent B-cell non-Hodgkin lymphoma (NHL). Only weeks later, Eagle won another FDA approval, this time for its generic docetaxel injection for treating breast cancer, non-small cell lung cancer, prostate cancer, gastric adenocarcinoma, and head and neck cancer. 

Bendamustine hydrochloride was given the brand name Bendeka and went on to become a big winner for Eagle and Teva. Commercial success of the drug helped drive Eagle's revenue up a whopping 186% in 2016. The company thinks it could have an even bigger winner with EP-5101, its ready-to-dilute version of Eli Lilly's Alimta. An approval decision by the FDA for EP-5101 is expected by Oct. 30, 2017.

Exelixis

Another biotech stock, Exelixis, is up even more than Eagle Pharmaceuticals over the last three years. Exelixis stock has soared nearly 550% during the period.

Exelixis' gains really picked up steam in May 2016 when the company announced initial results from a clinical study of Cabometyx as a first-line treatment for advanced renal cell carcinoma (RCC), a type of kidney cancer. The drug had already won FDA approval in treating RCC for patients who had received prior therapy. However, the market for first-line treatment of RCC is significantly larger and presented tremendous growth opportunities for Cabometyx -- and Exelixis. The company plans to submit for approval in the new indication in the third quarter of 2017.

Female scientist in lab

Image source: Getty Images.

More good news for Cabometyx could be on the way. Exelixis' executives said in the biotech's first-quarter earnings call in May that a second independent data monitoring committee review of a study evaluating Cabometyx as a second-line treatment of liver cancer is expected in the second half of this year.  

NVIDIA

The best-performing stock isn't a biotech, though: It's NVIDIA. Shares of the technology company are up more than 730% over the last three years.

NVIDIA has benefited from being in the right place at the right time for several huge technology trends. The company's graphics chips are in high demand for gaming. NVIDIA's expertise in this area also makes it one of the best virtual reality stocks on the market. In addition, the company has expanded its focus to include artificial intelligence (AI). And don't overlook NVIDIA's potential in the driverless car market.

The great news for NVIDIA is that all of these trends aren't likely to fizzle out anytime soon. The markets for virtual reality, AI, and driverless cars should only grow in size over the coming years. NVIDIA seems likely to be in the right place at the right time for a while to come.

Keith Speights has no position in any stocks mentioned. The Motley Fool owns shares of and recommends Exelixis and Nvidia. The Motley Fool recommends Teva Pharmaceutical Industries. The Motley Fool has a disclosure policy.