Total global commodity assets under management (AUM) were valued at $311 billion in December, up $3.1 billion from November and $45 billion from a year earlier, according to Barclays.

Commodity prices gained from economic growth, supply disruptions and increased geopolitical risk in 2017, which helped push investor AUM to multi-year highs, the bank said in a note.

Precious metals accounted for over 40 percent of the AUM at $131billion, followed by energy at $97 billion, the note said. "The markets closed out 2017 on a strong note, as commodities from energy to metals surged into year-end."

December saw an inflow of $3.4 billion in commodity investment compared with an outflow of $3.3 billion in November. Total investment in energy was $1.4 billion, followed by agriculture at $900 million and precious and base metals at $500 million each.

"The global economic outlook for 2018 remains robust, which should lend support to the broader commodity complex, but idiosyncratic factors could cause commodities such as oil and copper to weaken from current levels," analysts at the bank said. REUTERS