NEW YORK — Wall Street headed for huge rebound Monday as investors, hoping that the stock market has reached a bottom after eight sessions of devastating losses, sent stock futures sharply higher hours before the opening bell. The market appeared relieved by pledges of further coordinated actions by European and U.S. authorities to aid the crippled banking system, including plans by the Treasury to buy U.S. bank stocks.

Dow Jones industrial average futures rose 398, or 4.76 percent, to 8,768. Standard & Poor’s 500 index futures rose 51.30, or 5.76 percent, to 942.30.Nasdaq 100 index futures rose 62.00, or 4.83 percent, to 1,344.50.

Investors in Asia and later Europe were already buying, grabbing stocks after last week’s rout and action by major governments over the weekend to bolster investor confidence.

Overseas, Hong Kong’s Hang Seng index surged 10.2 percent. Markets in Japan were closed for a holiday. In morning trading, Britain’s FTSE 100 jumped 4.27 percent, Germany’s DAX index rose 5.61 percent, and France’s CAC-40 6.08 percent.

Still, while the markets were upbeat early Monday, they were also well aware that there is much to be done to heal the banking system and the credit markets that have come to a virtual halt. Moreover, even if there is heavy buying when trading opens Monday, Wall Street can expect to see back-and-forth trading in the coming days and weeks as investors remain very nervous.

Investors awaited details of the U.S. plan to resuscitate the financial system following word from the Bank of England that it would use up to $63 billion to the three largest British banks to help shore up their balance sheets.

The Bush administration is working on implementing its $700 billion financial rescue plan. Neel Kashkari, an assistant Treasury secretary who is running the program on an interim basis, was expected to deliver a progress report on Monday.

The Treasury is expected to discuss plans to buy non-voting common or preferred stock in banks. That would get capital to financial institutions faster than the purchase of their soured mortgage-backed assets.

The Bank of England, the European Central Bank and the Swiss National Bank jointly announced plans to work together to provide as much short-term funding as necessary to help revive lending. The Bank of Japan said it was considering taking similar steps.

After a series of weekend meetings in Washington of heads of the Group of Seven nations, strong gains in markets in Asia and Europe signaled that investors found comfort from the actions and pledges coming from government officials.

Bond markets are closed for the Columbus Day holiday. The dollar was mixed against other major currencies.

The surge in stock futures comes after a dismal week on Wall Street that erased an estimated $2.4 trillion in shareholder wealth. The Dow, after eight consecutive daily losses that totaled just under 2,400, or 22.1 percent, finished at its lowest level since April 2003, and also suffered its worst weekly percentage loss ever, a fall of 18.2 percent.

Meanwhile, the S&P 500 lost 15.3 percent and the Nasdaq composite index fell 15.3 percent.

Investors worried that banks’ reluctance to lend to one another would imperil economic activity by making it harder and more expensive for businesses and consumers to get a loan.