Stocks end lower after a turbulent week

The Dow closed 0.9%, or 245 points, lower, on a second-straight day of losses. The S&P 500 and the Nasdaq Composite both finished down 1.1%. It was the third day of losses in a row for both indexes.

Worse still, it was the third round of weekly losses for the S&P 500 and the Nasdaq Composite, making for their longest losing streak since October and August 2019, respectively.

The Dow was mostly flat on the week, but its modest 8 point drop still meant it was its third down week in a row, it longest losing streak since October last year.

This rough patch began with a sharp selloff driven primarily by tech stocks, which had soared over the summer.

Investors have been pulled into different directions this week. On one hand, the Federal Reserve committed to keep interest rates lower for longer, which is good for companies wanting to borrow money -- and therefore good for the stock market.

Yet lower rates also mean the central bank doesn't expect a swift rebound back to normal, and that puts a damper on residual hopes for a V-shaped recovery.

Meanwhile, Congress still hasn't passed another fiscal stimulus package and Covid-19 infections are rising again around the world.

On a more technical note, Friday also marked what's known as "quadruple witching," which is the simultaneous expiration of stock and index futures and options. It can spur volatility in the market.