Oil prices: the biggest mover

The effects of the peace deal were most visible in energy markets. On Tuesday, June 16, Brent crude futures fell 4.4% to roughly $83.46 per barrel, hitting their lowest levels since before the Iran war began . By June 18, after the interim deal was signed in Switzerland, Brent traded below $79 per barrel . The deal is expected to lift sanctions on Iranian oil exports and reopen the Strait of Hormuz — a chokepoint for roughly one-fifth of global oil and gas — which had been blockaded during the conflict . S&P Global cautioned that physical crude markets would remain tight through the summer, but the long-term supply outlook improved markedly .

US Treasury yields: fell on softened Fed tightening expectations

Lower oil prices directly reduce inflation expectations, and that logic played out in US government bonds. The yield on the 10-year Treasury note declined following the announcement, with the Wall Street Journal reporting "Treasury yields and the dollar experience a downturn" as the peace deal took shape . By Tuesday, the 10-year yield had slipped to around 4.45%, down from 4.485% on the previous Friday . The reasoning was clear: cheaper oil softened expectations for further Federal Reserve tightening . This was also the week of the Fed's June 17–18 policy meeting. The Fed ultimately kept the federal funds rate unchanged at 3.50%–3.75%, but the dot plot revealed a split committee: 9 of 19 officials expected at least one rate hike within the year, and 6 advocated for 50+ basis points of cumulative tightening . The peace deal-driven oil drop made those hawkish expectations feel less likely to materialize.

Euro zone government bond yields: fell sharply, reducing ECB hike expectations

Europe saw an even more pronounced move. Euro zone government bond yields fell for a fourth consecutive day on Tuesday, hitting multi-week lows . The German 10-year Bund yield dropped 2.5 basis points to 2.925%, its lowest since April 8 . Italian 10-year yields also fell, dropping 4 basis points to 3.639% . The same mechanism was at work: the plunge in oil prices reduced imported inflation pressure for the euro area, which weakened expectations for European Central Bank rate hikes . Money markets priced in only 30 basis points of ECB tightening by year-end — a significant reduction from earlier hawkish pricing .

Policy divergence: Fed on hold, ECB holding steady, BoJ hiking

By mid-June 2026, the Fed and ECB were in clearly different positions — and the peace deal amplified the gap.

The Bank of Japan added another dimension to the divergence story, hiking its policy rate to 1% — a 31-year high — on the same Tuesday, citing inflation risks from the Middle East energy shock . Multiple analysts characterized the broader picture as a "great policy divergence," with the Fed at a cautious hold, the ECB in a steady pause, and the BoJ actively tightening .

Key takeaway

Tuesday, June 16, 2026, was not a flight to safety — it was the day the geopolitical risk premium collapsed. Falling oil prices from the US-Iran peace deal directly reduced inflation expectations, which lowered bond yields in both the US and euro zone and dampened expectations for further monetary tightening from both the Fed and the ECB. The broader move was an unwind of hedges: risk-on in equities and bonds, risk-off in oil and haven currencies.

Oil prices: the biggest mover

The effects of the peace deal were most visible in energy markets. On Tuesday, June 16, Brent crude futures fell 4.4% to roughly $83.46 per barrel, hitting their lowest levels since before the Iran war began . By June 18, after the interim deal was signed in Switzerland, Brent traded below $79 per barrel . The deal is expected to lift sanctions on Iranian oil exports and reopen the Strait of Hormuz — a chokepoint for roughly one-fifth of global oil and gas — which had been blockaded during the conflict . S&P Global cautioned that physical crude markets would remain tight through the summer, but the long-term supply outlook improved markedly .

US Treasury yields: fell on softened Fed tightening expectations

Lower oil prices directly reduce inflation expectations, and that logic played out in US government bonds. The yield on the 10-year Treasury note declined following the announcement, with the Wall Street Journal reporting "Treasury yields and the dollar experience a downturn" as the peace deal took shape . By Tuesday, the 10-year yield had slipped to around 4.45%, down from 4.485% on the previous Friday . The reasoning was clear: cheaper oil softened expectations for further Federal Reserve tightening . This was also the week of the Fed's June 17–18 policy meeting. The Fed ultimately kept the federal funds rate unchanged at 3.50%–3.75%, but the dot plot revealed a split committee: 9 of 19 officials expected at least one rate hike within the year, and 6 advocated for 50+ basis points of cumulative tightening . The peace deal-driven oil drop made those hawkish expectations feel less likely to materialize.

Euro zone government bond yields: fell sharply, reducing ECB hike expectations

Europe saw an even more pronounced move. Euro zone government bond yields fell for a fourth consecutive day on Tuesday, hitting multi-week lows . The German 10-year Bund yield dropped 2.5 basis points to 2.925%, its lowest since April 8 . Italian 10-year yields also fell, dropping 4 basis points to 3.639% . The same mechanism was at work: the plunge in oil prices reduced imported inflation pressure for the euro area, which weakened expectations for European Central Bank rate hikes . Money markets priced in only 30 basis points of ECB tightening by year-end — a significant reduction from earlier hawkish pricing .

Policy divergence: Fed on hold, ECB holding steady, BoJ hiking

By mid-June 2026, the Fed and ECB were in clearly different positions — and the peace deal amplified the gap.

The Bank of Japan added another dimension to the divergence story, hiking its policy rate to 1% — a 31-year high — on the same Tuesday, citing inflation risks from the Middle East energy shock . Multiple analysts characterized the broader picture as a "great policy divergence," with the Fed at a cautious hold, the ECB in a steady pause, and the BoJ actively tightening .

Key takeaway

Tuesday, June 16, 2026, was not a flight to safety — it was the day the geopolitical risk premium collapsed. Falling oil prices from the US-Iran peace deal directly reduced inflation expectations, which lowered bond yields in both the US and euro zone and dampened expectations for further monetary tightening from both the Fed and the ECB. The broader move was an unwind of hedges: risk-on in equities and bonds, risk-off in oil and haven currencies.