Investors charged in to mining equities this week before retreating in the face of old threats, but they left a hint of optimism in a sector that some view as undervalued after a dramatic sell-off in the fourth quarter of 2008.

“Miners are now at one of the most oversold levels against the market in their history”, wrote analysts at MF Global, the commodities broker, in a report on Wednesday. “We believe that after having ignored the risks in the early summer, the market is now ignoring the positives.”