Gold has surged back above US$4,500 an ounce after the US Treasury announced it would significantly increase buybacks of longer-dated government bonds, a move that sent bond yields lower and revived demand for the precious metal.

In US trading, bullion climbed 3.8% to more than US$4,499 an ounce. The Treasury said it plans to at least double its buyback operations for longer-dated bonds, a step that helped ease pressure in the bond market after the 30-year Treasury yield had reached its highest level since 2007. Under the programme, which the Treasury revived in 2024 after a pause of more than two decades, the department repurchases older, off-the-run securities — a mechanism designed to improve liquidity in outstanding bonds and help manage the government's cash position.

The rally comes as investors remain focused on deteriorating US fiscal conditions and the economic uncertainty surrounding the Iran war. The Treasury's buyback announcement came only hours before the department disclosed that US public debt had surpassed US$40 trillion for the first time, a milestone that extends a fiscal trajectory already marked by credit-rating downgrades from major agencies.

For gold, lower bond yields carry particular significance because the metal does not generate income. Since bullion pays no coupon or dividend, the opportunity cost of holding it becomes less restrictive when yields fall — the dynamic that helped revive demand for the metal in the latest move. The investor bid also builds on a multi-year pattern in which central banks have been persistent net buyers of bullion, a layer of demand that sits apart from ETF and futures positioning.

The strength in bullion has also flowed directly into Australian gold stocks, where Ramelius Resources, Genesis Minerals, Regis Resources, Greatland Gold and Vault Minerals all recorded significant gains as investors piled into the sector. Australia is one of the world's largest gold producers, and local producers' revenues track the bullion price while mine operating costs adjust far more slowly, which is why gold-mining shares are typically more sensitive to bullion swings than spot gold itself.

The price action comes alongside a sharp reversal in flows into gold-backed investment products. Physically backed funds buy and hold bullion, so their flows translate directly into demand for the metal itself. Australian gold ETFs swung from $253 million of net outflows in June to $238 million of inflows in July, the biggest monthly turnaround on record.

In the United States, physically backed gold ETFs attracted roughly US$3 billion of net inflows in July, following two consecutive months of outflows.

For Australian gold investors, the combination of falling bond yields, a weaker US dollar and renewed investment flows is strengthening the backdrop for the country's gold producers. Because gold is priced in US dollars, a softer greenback lowers the metal's cost for buyers holding other currencies, compounding the effect of lower yields. Among the signposts ahead are the scale of the Treasury's buyback operations as they are carried out, monthly ETF flow data, and the question of whether bullion can establish itself above the US$4,500 level on a sustainable basis.