A market leader in solar microinverters, ENPH gained over 50% in the first ten trading days of 2017 alone.

Investing in penny stocks in 2017 was characterized by high volatility. While some companies like eventually saw massive multi-thousand percent gains after successful clinical trials, others such as Calibre Mining Corp. lost 50% of their value in the same year. Experts recommended reviewing 10-K filings and avoiding companies with "shady" advertising as these were major red flags. Top 10 Penny Stocks of 2017 - Yahoo Finance

A clinical-stage biopharmaceutical company that saw a staggering 628% year-to-date return in early 2017.