Lehman Brothers collapsed in September of 2008 after months of credit-crunched volatility, and various pundits have made comparisons to this year as sovereign debt woes in America and Europe caused wild market gyrations throughout 2011.

Also back in 2008, Goldman Sachs crunched through the figures to report that September was a bad trading month for US markets in the previous 57 years.

What prompted last night's carnage was the Federal Reserve Bank's decision to put downward pressure on longer term interest rates by "twisting" the yield curve on US government bonds.

But investors in the US and Europe expected more stimulus than what has been labelled as "operation twist" - resulting in widespread market sell offs.

While the damage was done overnight, PNGIndustryNews.net will stay true to form and review the changes over the past week.

London Metal Exchange cash copper prices closed at $US7653 a tonne last night - down a frightening 11.7% since Friday.

LME cash nickel prices closed at $18,855/t overnight - diving 12% from the end of last week.

The fall below $20,000/t is significant for this commodity, but if it slips below $15,000/t there could be major impacts for several Australian nickel operations.

Singapore Tapis crude closed at $118.70 a barrel overnight, a 3.6% haircut from last Friday - but falling oil prices could bring some welcome relief to various industries.

Spot gold is trading around $1744.85 an ounce, about 3.7% down from last Friday and indicating that some speculative gold investors have also been caught up in the tailwinds.

The Australian dollar, often linked to commodity prices and investor perceptions of the global appetite for risk, has slumped from $US1.036 at the end of last week to US98c in trading today.

Most stocks on our watchlists have slumped in accordance to the fallout on resource commodity prices.