Image source: Flickr user Christian Schnettelker.

No one knows where the market will go in any specific time period, but that doesn't stop us from making educated guesses on what we think could happen, and this past year was no exception. While these Motley Fool contributors didn't get all of their guesses right, these predictions were among some of their favorites.

Tyler Crowe: For more than two years now, even calling the coal industry a dumpster fire might be generous. The bloated balance sheets of companies across the space were dependent on higher coal prices. The problem, though, is that cheap natural gas started to take market share from coal in the electricity generation space. Since then, the coal industry hasn't been the same. So, for the second year in a row, I had a feeling that someone in the coal space would go bankrupt. That prediction came true when Alpha Natural Resources, at the time the third largest coal miner in the U.S., filed for chapter 11.

Even though the market for coal was as rough as it was, it was hard to imagine how hard it has actually hit the industry. One would have assumed that a large player or two going bankrupt would take production out of the market and bring up prices, but cheap natural gas just keeps putting downward pressure on coal prices. Even Peabody Eenrgy (BTU), the nation's largest coal producer and the only U.S. coal miner with significant operations overseas, is facing the problem of razor-thin profit margins that can barely service the company's debt load.

Unless we see some major uptick in coal prices, which will likely require a large uptick in natural gas prices as well, it's hard to see Peabody or other major debt-laden coal producers making it out of 2016 alive. 

Todd Campbell: One of the five predictions I made last January was that investors would flock to drugmakers crafting generic versions of expensive biologics, or biosimilars.

Historically, the complexity of top-selling biologics, which are made in living organisms, has kept sales insulated from generic competition; however, health reform's establishment of a pathway to approval that allows for drugs that work similarly, but aren't exact copies of biologics, is changing that. Given that $67 billion in biologics will lose patent protection by 2020, it's not hard to understand why I predicted that investors would gobble up shares in leaders like Hospira this year.

In February, Pfizer (PFE 2.40%) agreed to buy Hospira lock, stock, and barrel for $17 billion, and shares in other biosimilar plays also surged higher in 2015, including an 80% rally in Momenta Pharmaceuticals (MNTA) through July. Although it's given some of those gains back, Momenta Pharmaceuticals is still up a market-trouncing 29.5% year to date.

Can biosimilar stocks continue to run higher in 2016? Absolutely. Pfizer estimates that the market for biosimilars could hit $20 billion in the next five years, and if so, then biosimilars will significantly boost the top and bottom lines for Pfizer and its competitors, including Novartis' Sandoz, Amgen, and Momenta Pharmaceuticals.

Steve Symington: I know the only thing certain in today's business world is uncertainty, so I try to stay away from making hard and fast "predictions." But when all signs pointed to an impending long-term license and material supply agreement between LG Display (LPL 0.26%) and OLED Technologist Universal Display (OLED -2.06%) last December, I just had to point it out to our readers.

After all, Universal Display stock was still reeling after a weaker-than-expected quarterly report the prior month, caused in part by soft sales of Samsung's (NASDAQOTH: SSNLF) high-end smartphones featuring its flagship OLED technology. And Universal Display was still suffering uncertainty as some analysts speculated -- contrary to management's insistence otherwise -- that it was facing a patent cliff as early core IP expired in 2017, which happened to coincide with the expiration of UDC's existing long-term agreement with Samsung.

However, I noted at the time that Universal Display CFO Sid Rosenblatt had stated a few weeks earlier that LG Display had "committed billions of dollars toward OLED facilities, [and] we fully expect them to sign a license agreement."

But for that to happen, I knew LG Display's OLED manufacturing capabilities would need to grow enough to reach what Rosenblatt called a "crossover point" -- that is, where volume discounts under a long-term agreement would make it more economically feasible than the successive short-term agreements under which LG Display had operated to date.

"Judging by LG's current plans," I wrote in reference to the ongoing ramp of its Gen-8 OLED TV production line, "that could happen in the very near future. ... And when it does, as OLED technology continues to become more pervasive, Universal Display investors will be happy they held onto their shares."

Sure enough, in late January 2015, Universal Display stock skyrocketed 20% after it announced a long-term agreement with LG Display that runs through the end of 2022. As of this writing, shares of Universal Display are up more than 90% since my "prediction" that it would seal this deal, and I hope investors are happy indeed.