Stocks slip, day 2

NEW YORK (CNNMoney.com) -- Stocks slumped Friday morning, extending the previous day's decline, as mounting worries about the tightening of credit and the subprime mortgage fallout gave investors a reason to retreat.

Bond prices rose in tandem, sending the corresponding yields lower, as investors made a classic 'flight-to-quality' move into the comparatively safer haven of bonds.

The Dow Jones industrial average (down 147.71 to 13,122.97, Charts) lost nearly 100 points in the early going, after slumping 387 points in the previous session, its second biggest one-day point and percentage decline of the year.

The broader S&P 500 (down 19.86 to 1,433.23, Charts) index gave up 0.7 percent, adding to Thursday's nearly 3 percent slump.

The tech-fueled Nasdaq Composite (down 35.61 to 2,520.88, Charts) index tripped 1 percent, adding to the previous session's 2.2 percent slide.

Stocks slumped Thursday as worries about a tightening of the global credit market resurfaced, sparking a broad decline in stocks in the U.S. and abroad.

Those worries continued Friday, after the European Central Bank (ECB) pumped extra cash into the system for a second day in a row, as a means of calming nervous trader. The ECB added $83 billion in liquidity Friday.

The Federal Reserve followed suit, adding $19 billion in temporary reserves. The move was the biggest single temporary open market operation in four years, the New York Federal Reserve said, according to Reuters.

Stocks have been whipsawed over the last few months on fears about tightening credit after a period of widespread liquidity. At the same time, investors have been trying to sort out the implications of the fallout from the subprime mortgage market - loans made to consumers with less than ideal credit - amid the slumping housing market.

Stock declines were broad-based, with 25 out of 30 Dow stocks falling, led by American Express (down $0.95 to $59.70, Charts, Fortune 500), Alcoa (down $1.09 to $34.35, Charts, Fortune 500) and Boeing (down $1.81 to $96.49, Charts, Fortune 500).

In global trade, European stocks fell in the afternoon, and Asian markets ended lower.

Treasury prices rallied, sending the benchmark 10-year note yield down to 4.75 percent from 4.77 percent late Thursday. Bond prices and yields move in opposite directions.

In currency trading, the dollar was flat versus the euro and slumped versus the yen.

Oil prices fell, with U.S. light crude for September delivery slipping 93 cents to $70.66 a barrel on the New York Mercantile Exchange.