The S&P/ASX 200 Index (ASX: XJO) closed up 0.5% in June, but ASX 200 energy stocks including Santos Ltd (ASX: STO) and Woodside Energy Group Ltd (ASX: WDS) dragged on those returns.
On 29 May, Woodside shares closed the day trading for $30.66. On 30 June, shares ended the day changing hands for $28.21 apiece. This saw the Woodside share price down 8.0% in the month just past.
Santos shares also underperformed. Santos shares closed May at $7.81 and ended June trading for $7.21 each. This put the Santos share price down 7.7% in June.
But Santos and Woodside shares both held up considerably better than their two smaller ASX 200 energy stock rivals.
Closing out May at $1.08 a share and ending June at 86 cents, Beach Energy Ltd (ASX: BPT) shares tumbled 20.4% over the month.
Karoon Energy Ltd (ASX: KAR) shares had an even rougher month. The Karoon Energy share price closed out May at $1.96 and finished June at $1.46. This saw the Karoon share price down a steep 25.5%.
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Why did ASX 200 energy stocks tumble in June?
When every ASX 200 stock in a certain category materially underperforms the benchmark, there tends to be a common root.
In this case that shared root was another big leg down in the oil price in June, fuelled by ongoing peace negotiations between the United States and Iran and a partial reopening of the Strait of Hormuz.
Indeed, on 1 June, Brent crude oil was trading for US$95 per barrel. By 30 June, the oil price had sunk to US$73 per barrel, according to data from Bloomberg.
If sustained, that 23% fall in the global oil price will have a noticeable impact on the big Aussie oil and gas producers' profit margins and dividends.
Why did Karoon Energy shares lead the way down?
The more than 25% decline in the Karoon Energy share price in June can broadly be pinned on the full year 2026 production guidance downgrade at the company's joint venture Who Dat project, located in the US Gulf of Mexico.
Karoon reported the downgrade on 16 June. Shares in the ASX 200 energy stock closed down 11.6% on the day and fell another 13.4% the following day.
With damaged equipment to blame, Karoon lowered its 2026 production guidance from the project to between 1.2 million and 1.5 million net barrels of oil equivalent (boe). That's down from prior guidance of 2.1 million to 2.5 million boe.
Across all of its assets, Karoon decreased full year production guidance to between 7.2 million and 8.2 million boe, down from previous guidance of in the range of 8.1 million to 9.2 million boe.
