Now that excitement around the holidays has settled, it's time to consider what's in store for 2013. A great way to accomplish is by thinking about the big trends that investors are likely to encounter in the year ahead. More often than not, reviewing the previous year is a great starting point, because long-term trends take years to unfold, giving you valuable insight into the year ahead. Here's three themes you must consider for your portfolio today.

1. Big data growth
The last two years alone have created 90% of the world's data. Let that sink in for a moment. Every day, a mind-blowing 2.3 million terabytes of data is created and stored. This information age has created high demand for storage components, networking equipment, high-precision sensors, and new-age analytics. The mountains of unstructured data being created today do not line up nicely with the databases of yesteryear, requiring inventive ways to aggregate and process this information in an insightful manner. IDC estimates big data will grow at seven times the rate of the overall information and communication market, with revenue expected to reach $23.8 billion a year by 2016.

If you're looking for two of the biggest names in big data analytics, look no further than International Business Machines (IBM -8.47%) or Teradata (TDC -0.54%). With IBM, you get the whole package, from storage components to analytics, including Watson, IBM's innovative supercomputer that can understand natural language. In terms of analytics, IBM's business analytics segment revenue rose 14% year-to-date last quarter. However, since there's more to IBM than just data analytics, Teradata is better suited if you're looking for a pure-play data-oriented investment.

Last quarter, Teradata reported year-over-year EPS growth of 18%, on revenue that grew 10% after adjusting for currency fluctuations. With North American revenue making up 60% of Teradata's total business, there's a significant international growth opportunity for the company. Surprisingly, Europe has been Teradata's strongest growth area, with 28% year-over-year growth on a constant currency basis, but only makes up 24% of total revenue. Overall, the company has been growing, its profitability has been increasing, and it's in a strong position to pick up more business going forward.

2. Mobile payments boom
According to IDC, worldwide purchase volume on mobile devices will exceed $1 trillion by 2017. That's a lot of cheddar, which puts eBay's (EBAY -0.21%) PayPal service in a great position to benefit. As of last quarter, PayPal experienced a 14% year-over-year increase in active accounts, bringing the total to more than 117 million, or about 9 million more members than eBay.com claims. PayPal's revenue increased 23% year-over-year and its total transaction volume rose 20% to $35.2 billion. The company expects $10 billion in transactions will come from mobile in 2012.

In terms of profits, PayPal has become a massive growth driver for eBay. On a year-over-year basis, PayPal's quarterly profit grew by over 43%, handily surpassing eBay marketplace's 10% growth in profit. What defines PayPal as a great contender to win the mobile payments war is convenience. It's as easy as paying with an email address and password on a smartphone. Compared to the competition, PayPal's expansive network and growing network puts it in a better position to win.

3. Additive manufacturing
The 3-D printing industry is red-hot right now. Companies like 3D Systems (DDD -0.86%) and Stratasys (SSYS -1.93%) sit at the center of the 3-D printing revolution for investors, and both companies have seen shares skyrocket over the last year. Currently good for $1.3 billion a year in business, the 3-D printing industry is expected to balloon to $5.2 billion in eight years' time. Considering that Stratasys and 3D Systems only expected to bring in a combined $641 million in sales this year, there is still plenty of room for growth for both players. IDC has predicted that 2013 will be another year that additive manufacturing evolves rapidly. If true, future printers could make predecessors look inferior -- a good thing for printer companies like 3D Systems and Stratasys.

The year ahead
While I can't say with 100% certainty these investment ideas will pan out as expected, I can say there's a pretty good chance that these themes will continue to assert themselves in 2013. When you invest for the long term, it's a great idea to first identify overlying growth areas and then find investments that are in great position to benefit.