One of the most noteworthy parts focused on Burlington Northern, Berkshire's railroad business. After being rather critical of the business last year, Buffett was more upbeat on the railroad following its 2015 operations, said Cramer, the co-manager of the Action Alerts PLUS portfolio.
"They came back very strong in 2015" and were much more competitive, Cramer added. However, 2016 will be a tough year, mainly due to coal prices.
Excluding coal and crude oil, Cramer said the letter made him feel more positive on the railroad industry.
Share prices for the major public rail companies have suffered over the past year, falling roughly 30% apiece. However, Cramer argued that if management from CSX (CSX) - Get Report , Norfolk Southern (NSC) - Get Report and Union Pacific (UNP) - Get Report would get it together, these stocks would have room to rally.
These three stocks "may be too cheap," Cramer said, "I would look at all three." It's the companies' inefficiencies that are holding back the stock prices. Perhaps it will ultimately lead to consolidation, he concluded.
At the time of publication, Cramer's Action Alerts PLUS had no position in companies mentioned.