Warren Buffett’s Berkshire Hathaway (NYSE:BRK-A) has been under pressure. Last year, the conglomerate reported its worst run since 2008, with shares dropping by nearly 13%. Since then, shares haven’t recovered. The S&P 500 (INDEX:SPAL) has fared much better with a decline of 7.9% since the beginning of last year.

Source: Berkshire Hathaway stock price chart by amigobulls.com

The weakness is due, in large part, to the soft commodity price environment. Berkshire does not have direct exposure to commodities since it does not own resource producers, but its subsidiaries, such as the railroad and manufacturing businesses, rely on the commodities sector for revenues. Furthermore, the cheap fuel prices at gas stations have already led to an increase in driving activity which could lift the number of road accidents, dimming the prospects of Berkshire’s insurance business. On top of this, the poor performances of IBM (NYSE:IBM) and Wells Fargo (NYSE:WFC), two of Berkshire’s biggest investments, have also dragged Berkshire stock.

Following the drop, Berkshire stock is now trading at just 1.3 times book value. That’s slightly higher than the implied floor of 1.2 – a level where Buffett has said that he would be willing to buy back stock. I believe that in the short term, Berkshire stock may continue to remain under pressure due to fears about the US economy and persistent weakness in commodity prices. But Berkshire investors shouldn’t panic since the company’s long-term future, driven in large part by some of its biggest investments that make up more than 50% of its US long portfolio – IBM, Wells Fargo, Coca Cola (NYSE:KO) and Kraft Heinz (NASDAQ:KHC) – is still looking bright.

IBM and Wells Fargo have been notable underperformers. The technology giant’s shares have declined 18% since the start of 2015 while the big bank stock has fallen 13% in the same period. IBM has taken a beating due to its anemic growth. The big blue’s sales have been shrinking for the last four years. But it is still a cash flow machine that loves to reward shareholders through dividends and buybacks.