2015 was a relatively calm year for initial public offerings on Wall Street, especially in comparison to 2014, which saw the biggest IPO ever with Alibaba Group Holdings BABA. Only 169 companies made their market debut, including Fitbit Inc FIT, Ferrari NV RACE, Shake Shack (SHAK – Snapshot Report), GoDaddy Inc GDDY, and Spark Therapeutics ONCE.

Some of the biggest IPO rumors—Uber, Airbnb, Pinterest, and Snapchat—remained privately-held and were able to raise boatloads of money without listing on a stock exchange. But that hasn't stopped these four companies from still leading the IPO pack in 2016. For more information on each of these buzzed about companies, click here for our free report on their IPO potential in 2016.

In addition to the tech industry, other business sectors have fueled IPO rumors just as much. Let's take a look at five other companies who show great IPO promise for 2016.

1. Palantir

Founded in 2004, Palo Alto, California-based Palantir Technologies Inc is a data analysis company that has made a name for itself over the years. For instance, its pattern detection technology has been credited with exposing the infamous Bernie Madoff Ponzi scheme as well as aiding the Central Intelligence Agency (CIA) in capturing Al Qaeda terrorist Osama Bin Laden.

As of October 2015, Palantir is valued at $20 billion, with total equity funding reaching $1.2 billion. Despite some critics debating over whether its business—sorting through tons of secret data—may be better suited for an acquisition, an IPO for Palantir could help the company grow considerably.

2. SoulCycle

 After filing to go public last July, SoulCycle, a boutique spin class studio company that has turned into a nationwide phenomenon, is expecting to raise $100 million from its IPO. The company has 38 studios across the country and an estimated 300,000 loyal customers. SoulCycle was founded in 2006 and was eventually acquired by luxe fitness brand Equinox Fitness in 2011.