By Bret Kenwell Railroad stocks are under pressure due to new worries over the threatened rail strike. Here’s how to trade Union Pacific and CSX stock. The list of worries continues to grow as the year wears on. Inflation, geopolitical turmoil, energy prices, increasing rates and rising food prices have all topped the list so far. The latest addition? A potential rail strike in the US. Inflation came in hotter than expected on Tuesday, the PPI report was mixed today and now there’s a new festering risk to the U.S. economy. As reported earlier by TheStreet: “A possible strike by unionized worke…