If you want to be a successful investor, you have to think ahead and anticipate the trends that will create the next big thing. Yet that can be hard to do, especially when the industries that will capitalize on those trends might not even exist yet.

Nevertheless, it's worth looking at some potential money-making opportunities at the cutting edge, and we've turned to a group of Motley Fool contributors to tell us where they think you can find some. Read their thoughts and then add your own in the comments below.

Todd Campbell: The next big investment might be tied to a seismic shift that's about to occur in biotechnology.

For years, drugmakers of traditional small molecule drugs have had to endure the pain of market share losses to generic counterparts, but biologics' tough-to-copy nature has made biotech bellwethers immune to that risk.

However, that's about to change. In March, the FDA approved the first biosimilar -- a copy of Amgen's blockbuster Neupogen made by Novartis -- and the agency followed that up with the approval of a generic version of Teva Pharmaceutical Copaxone in April.

More approvals of biosimilars are likely to be coming, too. Roughly $70 billion in branded biologics are expected to be off-patent by 2018 and that's got companies like Pfizer, Amgen, and Biogen plowing big money into biosimilar research and development. Since biosimilars are likely to carry prices that are 30%-40% less than branded biologics, cost-conscious payers are likely to flock to them, creating significant investment opportunities along the way. 

Hand holding a glass of water with plants in the background

Image source: Getty Images.

Selena Maranjian: One often overlooked investment area is in front of us multiple times a day: water. We in the developed world may take it for granted, as it comes cleanly out of faucets on demand. But according to the World Health Organization and UNICEF, at least 1.8 billion people worldwide are estimated to drink contaminated water. More than 840,000 people die from water-related diseases each year. The world's population of about 7 billion people is expected to keep growing, surpassing 9 billion by 2050. These billions of people do and will need access to clean water -- and they'll also need food. That means agriculture is poised to grow -- and irrigation accounts for about 70% of global demand for water. In the U.S., too, many cities need to upgrade their water facilities. A lot of them have been constrained by budget pressures, but they can't put off such work forever.

You probably get the picture by now. There is great need for water worldwide -- treating it, purifying it, conserving it, recycling it, and so on. And much of that work will be done by companies in which we can invest. In the U.S., for example, we have American Water Works Company and American States Water Company, both with positive free cash flow and double-digit net margins. Even bigger is Veolia Environment, of France. All three are involved in water infrastructure projects and water and wastewater services

If you're not ready to commit to one or two particular water companies, you might just opt for the Guggenheim S&P Global Water ETF, which will immediately park you in about 50 water-related companies. It has a not-exorbitant expense ratio of 0.65% and it has outpaced the world market over the past five years.

Sean Williams: If I were to say "personalized medicine" you'd probably extoll that this is far from an overlooked "next big thing," with the Apple Watch and other wearables, as well as targeted drugs, making the doctor-patient relationship more precise. However, it's easy for Wall Street and investors to forget that falling genome mapping prices could very well create a DNA-mapping revolution among the public in the coming years.

According to the National Human Genome Research Institute, the cost to sequence a human-sized genome ran a not-so-economical $95 million in September 2001. By July 2014, the average cost to sequence this same human-sized genome had fallen to just $4,905. As genome-screening technology improves in both speed and accuracy its costs should fall, and it may even become practical for insurers to offer coverage of a genome-screening test in order to discover potentially chronic or high risk conditions ahead of time for its members, which could save insurers millions or billions in long-term medical expenses.

One company leading this charge is Illumina, which develops a broad array of genome-mapping tools. Last year, with the introduction of the HiSeqX Ten Sequencing System, Illumina breached the $1,000 price point. Its genetic analysis machine is 10 times faster than its previous models, and it's able to map an entire human genome for less than $1,000.

To be fair, genome-mapping technology hasn't necessarily translated into a significant number of drug developments as of yet, but the technology behind targeting certain genes is still in its infancy among drug developers. Give this technology time and I suspect it could become the next big thing.

Dan Caplinger: One controversial investment opportunity involves climate change and the impact that rising temperatures could have on coastal areas. With so much of the world's population living on or near coastlines, any increase in sea level stemming from melting polar icecaps and other glacial areas could have catastrophic effects on existing infrastructure and require huge efforts to protect property from inundation and other collateral damage.

Many areas are already responding. In the Netherlands, the government is spending tens of billions of euros toward multiple efforts aimed at dealing with rising sea levels, including reinforcement of existing dikes, new designs for floating structures, and strengthening barriers to prevent water surges. The same Dutch companies that have helped meet their domestic needs are also going abroad, with engineering firm Arcadis entering into contracts in the New York City area to bring water-treatment plants back on line after Hurricane Sandy.

As attention grows, the demand for similar engineering services aimed at preventing problems and in dealing with the consequences of inadequate planning will rise substantially, and that could make Arcadis and other players in the field big winners from the trend. With a host of other potential climate-change impacts, smart investors are already trying to figure out second-order effects and looking at the companies that can profit from them.