LONDON (Reuters) - A look at the day ahead in U.S. and global markets by Dhara Ranasinghe.

As a combative U.S. presidential debate grabs attention, upcoming U.S. inflation numbers have fallen into the background -- but perhaps only temporarily.

After all, the August consumer price inflation report released later on Wednesday is the last big data release before a much anticipated Sept. 18 Federal Reserve rate decision.

And given that markets still attach a roughly 35% chance to an aggressive 50 basis points cut next week (a 25 bps move is fully priced in), the latest numbers have the scope to move traders' rate bets and therefore broader markets.

Economists polled by Reuters forecast a 0.2% month-on-month rise in both the headline and core consumer price index, with the headline annual measure expected to fall to 2.6% in August from 2.9% in July.

That would be the lowest annual inflation number since March 2021 and could cement expectations for a modest rate cut next week, which could support the dollar.

For Deutsche Bank economists, rental inflation is one to watch as there was a surprise rise in July, so the question is whether this was a one-off or not.

Ahead of the CPI release, markets appear to be taking their cue from Tuesday's debate between Democratic candidate Kamala Harris and Republican rival Donald Trump - after which pop megastar Taylor Swift said she would vote for Harris.

U.S. Treasury yields are lower, while the dollar (and bitcoin) as well as U.S. stock futures are broadly softer, in what is seen as a signal from markets that the debate has given Harris an edge ahead of the Nov. 5 presidential election.

Following the debate, online betting site PredictIt showed Harris' odds of winning improving 3 cents to 56 cents for a $1 payout, while Trump's chances dropped 5 cents to 47 cents.

The 10-year U.S. Treasury yield touched 3.605%, its lowest since June 2023, while the dollar was at 141.68 yen.

Budget forecasters' estimates so far suggest Trump's agenda would pile on more new federal debt.

A sale of 10-year Treasuries later on Wednesday should offer a taste of investor appetite for U.S. government debt.

Bank stocks could also be in focus a day after falling sharply.

The Fed's regulatory chief on Tuesday outlined a plan to raise big banks' capital by 9%, significantly easing an earlier proposal after intense Wall Street opposition but disappointing bank investors and some critics of the rule.

That coincided with some downbeat comments from the banking sector -- on Tuesday, JPMorgan Chase tempered expectations about income from interest payments and late Monday, Goldman Sachs CEO David Solomon said trading revenue could fall 10% this quarter.

In Europe, meanwhile, Italy's UniCredit said on Wednesday it had acquired a 9% stake in Commerzbank and will seek approval to potentially buy more, in a move that raised the prospect of CEO Andrea Orcel preparing to take over the German lender.

Key developments that may provide more direction to U.S. markets later on Wednesday:

* U.S. August CPI

* U.S. 10-year Treasury auction

(Reporting by Dhara Ranasinghe; Editing by Amanda Cooper and xxxx)