Oil

Oil prices have lost almost a third of their value since early October.

Gary Kaltbaum sees many bearish signs that investors need to keep an eye on.

Investor optimism returned to Wall Street.

Oil markets are also being affected by a downturn in wider financial markets.

Gas prices have fallen amid a record-setting slump in the U.S. oil market.

Oil prices slumped more than 6 percent to the lowest in more than a year on Friday amid fears of a supply glut even as major producers consider cutting output.

High production comes as the demand outlook weakens on the back of a global economic slowdown.

America is the world's biggest energy producer.

Concerns about overproduction have roiled the oil market.