* JPMorgan edges down after results
* Citigroup, Johnson & Johnson climb after earnings
* Futures up: Dow 93 pts, S&P 14.25 pts, Nasdaq 31.5 pts (Updates prices, adds premarket actives)
By Chuck Mikolajczak
NEW YORK, Oct 14 (Reuters) - U.S. stock index futures rose on Tuesday, after the S&P 500 suffered its worst three-day drop since November 2011, as investors digested earnings from a trio of large banks.
JPMorgan Chase shares edged down 0.8 percent to $57.70 in premarket, after the biggest U.S. bank posted third-quarter earnings. The results were released earlier than anticipated on an investment website ahead of its official release on Tuesday.
Fellow banks Citigroup gained 1.9 percent to $50.87 while Wells Fargo shed 0.4 percent to $50 after posting quarterly results.
The benchmark S&P closed below its 200-day moving average for the first time since Nov. 16, 2012 on Monday and is now down 6.8 percent from its record closing high on September 18 on concerns global economic weakness could hurt U.S. earnings and the potential spread of Ebola.
The CBOE Volatility index ended Monday's session at 24.64, its highest close since June 2012.
S&P 500 companies are expected to show earnings growth of 6.4 percent in the third quarter, according to Thomson Reuters data, with revenue growth expected at 4 percent. After the close, Dow component and chipmaker Intel is set to post results.
Johnson & Johnson shares were up 1.6 percent to $100.69 in premarket trade after the diversified healthcare company reported better than expected quarterly earnings.
Ebola-related stocks were once again among the most active in premarket trade on continuing concerns about the possible spread of the virus.
Lakeland Industries, a maker of garments to guard against hazardous materials, was down 6.7 percent to $27.07 before the opening bell. The stock has risen for seven straight days for a gain of nearly 250 percent. Versar Inc, a project management company that has a hazardous waste segment, jumped 31.9 percent to $4.75 in premarket trade.
* S&P 500 e-minis were up 14.25 points, or 0.76 percent, with 421,083 contracts changing hands.
* Nasdaq 100 e-minis were gaining 31.5 points, or 0.83 percent, in volume of 48,650 contracts.
* Dow e-minis were up 93 points, or 0.57 percent, with 57,898 contracts changing hands. (Reporting by Chuck Mikolajczak; Editing by Chizu Nomiyama)