The S&P/ASX 200 (Index: ^AXJO) (ASX: XJO) is bleeding chips today, and one of its recent top performers is the one now doing most of the damage.
Shares of BHP Billiton Limited (ASX: BHP) have been on a roll in the last few months, soaring on the back of rebounding iron ore and oil prices. From a low of just $14.06 earlier in the year, the shares were trading for as much as $19.96 during yesterday's session but have since come falling back down to earth.
They have dropped 3.6% today alone, and 5.3% since hitting that high, to trade at $18.90, while Rio Tinto Limited's (ASX: RIO) shares have also fallen 2.4%. That comes after BHP's London-listed shares also fell 3.1% overnight, with Rio Tinto's London shares also dropping 2.4%.
It appears the slump in BHP's share price can be attributed to a pullback in the price of copper. Copper, which is one of the miner's core commodities, is in high supply right now with stockpiles around the world growing. Part of that is due to a decline in demand from China as its economy slows down, with the supply and demand imbalance forcing the price lower.
At the same time, oil prices also suffered a setback overnight. Although oil prices remain well above the low levels they traded for earlier in the year, there is still uncertainty regarding the sustainability of the rally, and whether producers will take advantage of the upswing in price to flood the market with fresh supplies once again (which would likely force the price lower).
Like copper, oil is one of BHP's most important markets, so a pullback in the price is seen as a negative for the miner.
Indeed, BHP's shares have enjoyed a remarkable run over the last few months. The strong rally in price has likely been enough to tempt some investors back into the miner's shares, with some wondering whether today's dip is another opportunity to load up on the Big Australian.
In the near-term, there is every chance that BHP's shares could climb higher. After all, iron ore is still trading above US$52 a tonne and oil prices could rebound again from here. However, there is also a high level of uncertainty regarding the mining space in the medium and long-\ terms, which could have a material impact on BHP's shares, over time.
At $18.90 per share, I just don't think the risk versus reward trade-off is balanced in investors' favours. The shares could rise higher, but I'd be much more willing to put my money behind some of the market's other attractive opportunities rather than take a chance on BHP.