Investors increased their gold holdings in June, bringing the Gold Investor Index to 54.6. The spike eclipsed February's strong rebound from 5-year lows.

Investment demand for the precious metal rose in the first half of this year at its fastest pace since late 2012 by weight. Investors added more than 1.4 tonnes of gold to their total holdings since the start of the year – triple the amount during the first six months of 2014 – bringing total gold holdings to more than 34 tonnes.

“2015 has seen both sentiment and prices hold much steadier, consolidating as investors begin to query the high valuations put on equities and the record-low yields paid by government debt,” said BullionVault's head of research, Adrian Ash.

“Most notably, existing bullion owners have become much stickier, avoiding sales on both spikes and dips as the economic back-drop starts to make the case for holding rare, indestructible and instantly tradable gold very plain once again.”

Ash commented on the gold investment spike in relation to gold's “safe haven” status amid Greece's ongoing debt crisis. He highlighted that gold prices have not yet reacted to the prospect of a Greek exit from the eurozone, or “Grexit”, because the crisis for now remains Greece's alone.

“Money managers have yet to take fright. It would be irrational if not greedy or ghoulish to expect gold's function as financial insurance to pay off in the absence of broader investment stress.”

BullionVault based its trading data on the investment activity of 56,000 users in 175 countries worldwide. Almost 90 per cent of BullionVault users live in Western Europe or North America.