The S&P/ASX 200 index was up 0.3%, or 15 points, to 5430.

Trading was marked by the momentum of overnight gains on Wall Street but also some trepidation related to growing speculation the Australian dollar (last trading at US94.87c) had become dangerously overvalued.

Bloomberg data suggested today that the Aussie was 28% overvalued against the greenback based on purchasing power parity.

“The RBA has been counting on a gradual depreciation,” Pioneer Investment Management currency strategy director Paresh Upadhyaya was quoted as saying.

“But it hasn’t worked that way, largely because of the delay [in the US Federal Reserve reducing monetary stimulus].

“From a long-term perspective, the Aussie is a clear sell.”

For exporting Australian miners, this outlook seemed to offer little comfort as the basic materials sector posted one of the weakest performances on the ASX, down 0.2%.

BHP Billiton gained 0.2% to $A37.67 while Rio Tinto budged only 0.05%% higher to $63.44.

Gold companies followed a 0.5% overnight drop in the price of the precious metal to $US1345 per ounce, with Perseus Mining falling another 12.3% to A46.5c after its quarterly report prompted a 16.5% drop in yesterday’s session.

Evolution Mining fell 6.6% to 84.5c while Kingsgate Consolidated dropped 3.9% to $1.47 and sector giant Newcrest Mining closed 2.1% lower at $10.67.

Copper companies were also lower, with standouts including Avalon Minerals down 16.7% to 0.1c and Straits Resources down 11.1% to 0.8c.

Copper-cobalt producer Tiger Resources and nickel explorer Sirius Resources each went into trading halts today pending announcements related to a capital raisings.