* JPMorgan down on weak trading revenue estimate
* BofA also warns on trading revenue, down 2.2 pct
* Goldman top drag on Dow
* Oil touches 3-week low
* Indexes down: Dow 0.15 pct, S&P 0.21 pct, Nasdaq 0.26 pct (Adds quote, updates prices)
By Sweta Singh and Tanya Agrawal
May 31 (Reuters) - U.S. stocks were down on Wednesday as financials tumbled after JPMorgan and Bank of America hinted at revenue weakness in the current quarter and oil prices fell to a three-week low.
JPMorgan blamed lower volatility for the decline in trading revenue, while Bank of America said trading revenue in the second quarter was on track to be 10-12 percent lower than last year.
Measures of market volatility are at rock-bottom, hitting trading desks at big banks. The U.S. stock market's main gauge of investor anxiety closed at its lowest level in over two decades on May 8.
"There is a choppy sideways market due to the fact that fundamentals are largely unchanged and expectations of market friendly policies in the U.S. are being pushed to 2018," said Stephen Wood, chief market strategist, North America, Russell Investments.
Financials, which have largely outperformed the broader market on bets of fiscal stimulus and simpler banking regulations under President Donald Trump, are on track to decline 0.7 percent so far this year.
JPMorgan was down 2 percent on Wednesday. Goldman Sachs fell 3 percent and was the biggest drag on the Dow. Bank of America was down 2.5 percent.
Adding to the pressure, oil prices fell as rising Libyan production fueled concerns that OPEC-led output cuts are being undermined by several countries that are excluded from the deal.
"With oil also down, the thoughts of an economic slowdown start to come up in people's minds and has created a pause in the market euphoria," said Andre Bakhos, managing director at Janlyn Capital in Bernardville, New Jersey.
Seven of the 11 major S&P sectors were lower, with the financial index's 1.13 percent fall leading the decliners.
At 12:31 a.m. ET, the Dow Jones Industrial Average was down 30.8 points, or 0.15 percent, at 20,998.67, the S&P 500 was down 5.1 points, or 0.21 percent, at 2,407.81 and the Nasdaq Composite index was down 16.44 points, or 0.26 percent, at 6,186.75.
Shares of Michael Kors fell 9.9 percent to $32.69 after the luxury fashion retailer gave a bleak full-year forecast and said it would shut more than 100 full-price retail stores in the next two years.
Mallinckrodt was down 1.4 percent at $43.04, after sources said the drugmaker is exploring a sale of its generic drug unit, in a deal that could fetch as much as $2 billion.
Analog Devices rose 2.5 percent to $86.91 after the chipmaker's quarterly results came in above expectations.
Declining issues outnumbered advancers on the NYSE by 1,706 to 1,122, for a 1.52-to-1 ratio on the downside. On the Nasdaq, 1,678 issues fell and 1,057 advanced for a 1.59-to-1 ratio favoring decliners.
The S&P 500 index showed 28 new 52-week highs and 11 new lows, while the Nasdaq recorded 82 new highs and 70 new lows. (Reporting by Sweta Singh; Additional reporting by Yashaswini Swamynathan; Editing by Saumyadeb Chakrabarty)