Buffett buying railroads (BNI)

Legendary investor Warren Buffett disclosed a large position in Burlington Northern BNI. Two unnamed rails are also in the buy in. Buffett is usually early. He has to be because of the large size of the buys and sells. BNI has a nice looking chart and looks like a good buy on a pullback. Often times, there is a significant pullback below Buffett's entry point. This would be the natural expectation if he was buying and then is finished buying.