Sept 30 (Reuters) - A look at the day ahead in Asian markets.

Investors in Asia go into the last trading day of the quarter still riding high on the double dose of stimulus administered earlier in the month by the U.S. Federal Reserve and now by China.

In the latest move, the People's Bank of China on Sunday said it would tell banks to lower mortgage rates for existing home loans by Oct. 31. It is expected to cut existing mortgage rates by about 50 basis points on average.

This follows the slew of monetary, fiscal and liquidity support measures announced last week - China's biggest stimulus package since the pandemic - that triggered the most explosive stock market rally in years.

Japanese markets could be in for a rocky ride on Monday, however, as investors react to the news that former defence minister Shigeru Ishiba will be the country's new prime minister.

Ishiba has been a vocal critic of the Bank of Japan's past aggressive monetary easing, but said on Sunday that policy must remain accommodative as a broader trend, to underpin a fragile economic recovery.

The yen surged nearly 2% on Friday, and Nikkei futures are pointing to a sharp fall at the open on Monday.

The upside for markets on Monday may also be capped by investors closing their books for the quarter, and ahead of China's Golden Week holiday that starts on Tuesday.

Monday's calendar is loaded with major economic indicators, chief among them being China's official and unofficial purchasing managers index data. Also on deck are retail sales, industrial production and housing starts figures from Japan, GDP from Taiwan, and South Korean retail sales and industrial production.

China's markets could get a reminder of cold economic reality, with the National Bureau of Statistics PMIs expected to show that factory activity contracted for the fifth consecutive month in September.

Figures on Friday showed that industrial profits slumped 17.8% in August, the biggest decline this year. Citi's Chinese economic surprises index is hovering around its lowest level in over a year, in contrast to the U.S. surprises index, which is also in negative territory but still the highest in over a year.

It will take time for Beijing's stimulus to filter through to hard activity data, so investors may have to continue putting up with some sobering numbers in the coming weeks and months.

But the wave of optimism washing over markets is undeniable. Shanghai's blue chip equity index rose nearly 16% last week and the broader Shanghai composite jumped nearly 13%, both the biggest weekly gains since November 2008.

Hong Kong's benchmark Hang Seng index delivered its biggest weekly rise since 1998, and fifth largest in the last half century. Mainland Chinese property stocks, meanwhile, leapt 16%.

Here are key developments that could provide more direction to Asian markets on Monday:

- China official and unofficial PMIs (September)

- Taiwan GDP (Q2, final)

- Japan retail sales, industrial production (August)

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https://www.reuters.com/markets/asia/global-markets-view-asia-pix-graphic-2024-09-29/