U.S. stocks tumbled 12% on Monday after the Fed slashed rates to zero.

Federal Reserve slashing rates to zero, announces $700 billion bond-buying program.

Despite one of the worst weeks on record for stocks, investors added $2.9 billion to ETFs.

The index was last trading down more than 20% from its highs, the dividing line between a bull and a bear market.

These ETFs are moving the most on Monday.

Oil prices fall by their largest amount since 1991, fueling panic in the energy sector.

Year-to-date inflows moved up to $87 billion. 

The S&P 500 has dropped 10.6% in two weeks. Here are some ETFs that have done better and worse than that.

The Federal Reserve cut rates by half a percent on Tuesday, two weeks ahead of schedule.