Coming as federal policymakers and politicians work to craft a broad financial rescue plan, this morning's actions are meant as a short-term firewall against a steep market collapse, and demonstrate the government's willingness to change basic market rules, at a moment's notice, in response to the current crisis. The Treasury's move in particular marks an unprecedented step by federal regulators to guarantee the value of investments in a certain type of securities, suspending for money-market investors one of the basic rules of the marketplace - that value may go down. Previously, that sort of protection was offered solely to bank depositors.

Global stock markets soared towards what may prove historic one-day gains. The Dow Jones industrial average  added more than 225 points in the opening minutes of trading, or more than 2 percent. The tech-heavy Nasdaq added more than 5 percent initially while the broader S&P 500 jumped nearly 3 percent. Financial stocks, protected from short selling, enjoyed double digit gains, with investment banks Goldman Sachs and Morgan Stanley saw gains in excess of 20 percent.

European markets rose on the order of 7 to 9 percent, while Asian markets overnight added anywhere from 4 to 9 percent.

As with other recent steps taken by the government, Treasury's action to bolster money market funds seems to acknowledge that banks no longer stand alone at the core of the financial system.