Billionaire financier Warren Buffett's Berkshire Hathaway is all in, buying the rest of railroad firm Burlington Northern Santa Fe that it doesn't already own. The deal is Berkshire Hathaway's biggest-ever acquisition.

Buffett makes his biggest investment ever and it is in a railroad company.

I had to read this a few times to believe it, simply because you don't think of railroads as a booming industry. It is a mature business -- but then, this is what made Buffett. Patiently waiting for his investments to pay dividends instead of looking for short-term gains.

If you think about it the investment makes sense. As the economy picks up, there will be an increase in railroad traffic and that business will start making money again.

There is no question that profitability will come back. However, would it continue to grow?