Global stock markets soared on Friday, driven by massive gains by banks as governments worldwide stepped up their fight against the worst financial crisis in decades and news of the US government's full-frontal assault that included a massive plan to help save troubled firms drowning in soured assets. New changes to short-selling in the US, Britain and Ireland, also helped push markets higher, analysts said. Another factor was moves by the European Central Bank, Swiss National Bank and Bank of England to offer up more cash Friday. The three banks put a combined $90 billion into money markets in a lockstep move. The US government said it was putting together a comprehensive plan to ring a fence around the mountains of bad debt that have weighed down banks in the past year. The US Treasury said it would guarantee US money market funds up to an amount of $50 billion in order to ensure their solvency in another move to shore up the financial sector. In another move, the US financial watchdog, the Securities and Exchange Commission, banned the short selling of nearly 800 financial stocks – a move designed to remove one of the speculative pressures on the firms. President George W. Bush said Friday that US government intervention in financial markets is not only warranted but “it is essential” to calm nervous consumers and to halt the worst financial crisis in decades. “America's economy is facing unprecedented challenges. We're responding with unprecedented measures,” Bush said in a Rose Garden statement. Standing alongside were Treasury Secretary Henry Paulson, Federal Reserve Chairman Ben Bernanke and Christopher Cox, chairman of the Securities and Exchange Commission. Global stock markets roared higher after news of a possible US government plan to rescue banks from toxic mortgage debt. Wall Street extended a huge rally Friday as investors stormed back into the market, relieved that the government plans to rescue banks from billions of dollars in bad debt. The Dow Jones industrials rose more than 400 points, giving them a massive gain of more than 800 points over two days. In the first minutes of trading, the Dow Jones industrial average rose 412.31, or 3.74 percent, to 11,432.00. Broader stock indicators also surged. The Standard and Poor's 500 index rose 50.02, or 4.15 percent, to 1,256.53, and the Nasdaq composite index rose 85.82, or 3.90 percent, to 2,284.92. European exchanges, which had spent nearly all of this week drowning in declines responded with their own ferocity to the possible plan, surging as battered bank stocks rebounding along with them. London's FTSE jumped more than 8.7 percent, led higher by the Royal Bank of Scotland whose shares gained some 39 percent. In Paris, the CAC-40 Index was up up 7.7 percent while shares in Oslo rose nearly 8 percent. In Frankfurt, the DAX index sprung more than 5 percent higher with shares of Commerzbank AG and Deutsche Bank AG leaping 22.7 percent and nearly 19.5 percent, respectively. The Irish Stock Exchange responded with its biggest burst in Dublin trading history, rising more than 25 percent in the first hour. The financials-heavy index soon settled back on profit-taking, but remained up more than 12 percent. Irish regulators also banned short-selling on the stocks of the country's four largest financials: Allied Irish Banks, Bank of Ireland, Irish Life and amp; Permanent and Anglo-Irish Bank Corp. Russia's stock exchanges saw trading halted twice after a volatile session saw stocks shoot higher. They later resumed trading late in the day. Both RTS and MICEX bourses twice called a halt to trading after shares gained sharply, breaching technical limits. The dollar-denominated RTS climbed by 22.7 percent on Friday, while the MICEX soared by 31.4 percent. Austria's ATX surged past 11 percent in afternoon trade after opening about 8 percent higher earlier Friday. In Madrid, the SMSI was up nearly 7.2 percent while Swedish shares climbed 7.5 percent higher in Stockholm. In Belgium, shares gained 8.9 percent on the Euronext Bel-20. Across Asia, similar spikes were seen around the region. Hong Kong's Hang Seng Index surged a stunning 9.6 percent to 19,327.73, while Japan's Nikkei 225 average rose 3.8 percent to 11,920.86. In China, the Shanghai benchmark jumped 9.5 percent _ its biggest gain ever _ after the government eliminated a tax on share purchases and said it was buying shares in state-owned banks. Oil also rose more than $2 to above $100 on Friday.