As the markets roll into summer, the markets are close to all-time highs and investors are wondering how they should be positioned as the bull market is now over eight years old. Every pullback has been bought with aggression, and investors are looking for ways to make money outside of many traditional stocks.

Two industries that are known for making fortunes are biotech and emerging pharmaceuticals, within a broader health care sector. The analysts covering these companies often issue upside price targets of 50%, 100% or even more than 200%. Needless to say, that implies much more risk than normal in Dow and S&P 500 stocks that get upside calls of 8% to 15% when Buy and Outperform ratings are assigned.

24/7 Wall St. reviews dozens of analyst research reports each day of the week. This ends up being hundreds and hundreds of analyst calls over the course of each month. Of the universe of stocks and analysts we cover, there were seven speculative biotech and emerging pharma stocks given upside targets of close to 100% on the low-end and well over 200% on the high-end.

Investors in the biotech and biohealth space have to understand that they are taking on much more risk than with most Dow and S&P 500 stocks. That means they will demand more potential upside for that risk. After all, there is often a viability risk on top of just drug price risks and regulation or oversight risks. What is common among these speculative companies for exponential upside potential is that they are somewhat unknown and they all have market capitalizations of far less than $1 billion — and some are even in the micro-cap class with a value of under $100 million.

The risks in biotech are almost endless. Many biotechs fail to meet their drug study targets. Some only deliver mediocre sales results even after years of hype. And some of them ultimately implode and disappear entirely. Sometimes these companies go into zombie mode with no real developments for years (or ever again).

As with other analyst calls, investors need to consider that there is no such thing as a free lunch on Wall Street. Here are seven speculative biotech and biohealth stocks where analysts gave huge upside calls during the month of May 2017.

24/7 Wall St. has tried to offer some offsetting remarks or show risks about each company. It just wouldn’t be fair to show only the upside. After all, as noted, small cap and speculative biotechs often vanish after disappointments. And we wouldn’t want you thinking we only believe in big upside just because one analyst is predicting that.

Dicerna Pharmaceuticals Inc. (NASDAQ: DRNA) was started as Buy with a $5 price target at H.C. Wainwright on May 23. The prior closing price was $3.28, and it was last seen right at $3.00. While this speculative call was technically not a “double your money” call at the time, the reality is that Dicerna already has traded at $6.10 within the past year, and its market cap of just $63 million of late would indicate that any positive news could make for a rocket launch. This upside report suggests that several partners are likely for its preclinical GalXC drug candidates.

For the other side of Dicerna’s analyst views, two other less aggressive calls were made in May. Chardan issued a Neutral rating with only a $3.50 price target back on May 12. Leerink maintained its Market Perform rating with a $4 target on May 8, and that it has two additional new drug applications in the works for 2018.

Inovio Pharmaceuticals Inc. (NASDAQ: INO) was recently the beneficiary of positive study data in its HIV vaccine. While the stock popped by 25% to $8.90 in the immediate aftermath of the news, Inovio shares were last seen back down at $7.58. This stock is no stranger to volatility as the 52-week trading range is $5.83 to $11.62.