By Amanda Cooper

LONDON, June 29 (Reuters) - The dollar was headed for its biggest monthly gain in nearly a year on Monday, supported by the growing chances of rate rises and optimism about the U.S. economy, as investors watched developments in the Gulf ahead of ‌a key jobs report later this week.

The U.S. and Iran traded fresh attacks over the weekend before they agreed to stop and ‌meet in Qatar on Tuesday, leaving investors nervous about the declared ceasefire and nudging oil prices higher.

The euro edged up 0.2% to $1.14 after reaching a 13-month low against the dollar last week; ​it was on track for a 2.4% monthly decline.

The dollar index, which tracks the performance of the U.S. currency against six others, was steady at 101.34, near last week's 13-month high. The dollar itself has risen against every major currency this month, performing the strongest against Scandinavian and Antipodean currencies, which have lost between 4.7% and 7%.

Rising inflationary pressures, together with a surprisingly hawkish debut from Federal Reserve Chair Kevin Warsh, have upended market expectations for rate cuts this year, while the artificial intelligence-driven ‌boom in U.S. equity markets has been attracting capital ⁠at breakneck speed.

As such, the dollar is heading for a 2.5% gain for June, its biggest monthly rise since July 2025.

"That is quite significant because since April of last year, there's been so much discussion about the structural decline in the ⁠value of the dollar," Rabobank chief FX strategist Jane Foley said. "But I think, even if you vehemently believe that, you've got to admit that there is space for a cyclical uptrend."

"This is exactly what we have. Some of this can be attributed to the fact that the expectations around Fed interest rate hikes were later (in being priced ​in) than, ​say, for the Bank of England and European Central Bank, which hit right at ​the beginning of the war. But also, if we look ‌at the stock market, what we have -- particularly since the start of the war -- is this asset allocation very much in favour of the U.S."

Weekly data from the U.S. market regulator showed investors held their largest bullish position in the dollar relative to other major currencies since 2019, worth some $36.4 billion, according to LSEG data.

ECB FORUM, U.S. JOBS DATA IN FOCUS

Later this week, the monthly U.S. employment report could give investors a greater sense of how accurately markets are pricing the chances of Fed rate hikes this year. Right now, money markets show traders fully expect one rate hike this year, with a roughly 50% chance ‌of a second.

The Japanese yen was at 161.86, a touch weaker on the day ​and around its lowest point in 40 years, while the Swiss franc strengthened modestly for a ​third day to 0.8085, not far off last week's 11-month lows.

The ​pound was also steady on the day at $1.322, having touched its lowest in seven months last week. Labour politician Andy Burnham, ‌the top candidate to replace Keir Starmer as prime minister, ​told a gathering in Manchester on Monday ​he will not announce any government appointments until the end of the selection process.

Investors are keen to see who he appoints as finance minister, which could prove crucial for the outlook for both the pound and the gilt market. Burnham said any economic plans would be "backed by discipline" ​and abiding by the current fiscal rules.

Meanwhile, the ECB's ‌annual forum starts on Monday, opened by President Christine Lagarde, followed by a key policy panel on Wednesday that features Warsh, whose ​comments will come under close scrutiny from investors seeking more insight into the new Fed chief's thinking on the outlook for rates.

(Additional ​reporting by Jiaxing Li in Hong Kong; Editing by Thomas Derpinghaus, William Maclean)