It just goes to show: these days, exchange traded funds (ETFs) and the market can turn on a dime, and today was a perfect case in point.

This morning, things kicked off nicely off yesterday’s high. Financials were up, the price of oil was down. Investors were still aglow with the news that the Federal Reserve cut interest rates by three-fourths of a percent.

But it was a blink-and-you’ll-miss-it turnaround: the Dow Jones industrial average fell nearly 300 points, giving back much of its 420 points gained on Tuesday, reports Tim Paradis for the Associated Press.

The metals ETFs remained down: iShares Silver Trust (SLV) lost 5.8%, while streetTRACKS Gold Shares (GLD) declined 3.6%. Agriculture also finished lower: PowerShares DB Agriculture (DBA) lost 2.3%, while Market Vectors Global Agribusiness (MOO) declined 6.1%.

But financials, which were the early stars this morning, eventually lost steam and turned south again:

• Financial Select Sector SPDR (XLF), down 2.6%
• Regional Bank HOLDRs (RKH), down 1.1%
• iShares Dow Jones US Broker-Dealers (IAI), down 3.8%

The moral here is to not get swept up in the frenzy and keep emotions out of it. Strong performance is good, but it needs to be strong over a period of time - not just a day or two. Chasing performance can only turn into a fruitless and losing game of whack-a-mole.

Tags | Agriculture, DBA, Dow Jones Industrial Average, Federal Reserve, Financial, GLD, Metals, Silver