* Facebook up, CEO says no "meaningful impact" on ad sales
* Volatility index closes at lowest in more than 2 weeks
* Indexes up: Dow 1.0 pct, S&P 0.7 pct, Nasdaq 0.5 pct (Updates to close)
By Caroline Valetkevitch
NEW YORK, April 5 (Reuters) - The Dow and the S&P 500 posted gains for a third day in a row on Thursday, the longest streak in about a month, as investors' worries of an escalating trade conflict between the United States and China eased and their focus on upcoming earnings grew.
The Cboe Volatility Index, the most widely followed barometer of expected near-term volatility for the S&P 500, closed down 1.12 points at 18.94, its lowest close in more than two weeks.
Boeing, among the hardest-hit stocks on Wednesday after China retaliated with $50 billion in tariffs on U.S. goods, rose 2.7 percent, giving the Dow its biggest boost, followed by Goldman Sachs, up 1.3 percent.
"We're three to six months away from seeing anything, and in three to six months, there can be a lot of negotiating. It wouldn't take much to make this a less dramatic issue," said Peter Tuz, president of Chase Investment Counsel in Charlottesville, Virginia.
Optimism over first-quarter earnings increased, with JPMorgan Chase and other financials expected to kick off the reporting period next week.
"We're going into earnings season with a fair amount of optimism, largely driven by the new, lower tax rates and also driven by other bits of evidence the economy is doing very well," Tuz said.
Earnings forecasts have increased sharply since Congress approved sweeping changes to the U.S. tax law late last year, with first-quarter earnings growth expected to be the highest in seven years.
The Dow Jones Industrial Average rose 240.92 points, or 0.99 percent, to 24,505.22, the S&P 500 gained 18.15 points, or 0.69 percent, to 2,662.84 and the Nasdaq Composite added 34.45 points, or 0.49 percent, to 7,076.55.
Advancing issues outnumbered declining ones on the New York Stock Exchange by a ratio of 2.76 to 1, while it was the first day of more new 52-week highs on NYSE than 52-week lows since March 13.
On Wednesday, the Dow dropped more than 500 points after China and the United States imposed tariffs on each other's products, but closed up 230 points after President Donald Trump's top economic adviser Larry Kudlow said the administration was involved in a "negotiation" with China rather than a trade war.
Facebook, Amazon, Alphabet and Netflix - collectively known as the "FANG" group - were up between 0.3 percent and about 3 percent.
Facebook Chief Executive Mark Zuckerberg said the company had not seen "any meaningful impact" on usage or ad sales since the data privacy scandal.
Amazon rose 2.9 percent after being repeatedly hammered this week by Trump's attacks on the online retailer.
About 6.4 billion shares changed hands on U.S. exchanges. That compares with the 7.3 billion daily average for the past 20 trading days, according to Thomson Reuters data. (Additional reporting by Sruthi Shankar in Bengaluru; Editing by Sriraj Kalluvila and James Dalgleish)