What a tangled web the Brexit weaves.  On news that public sentiment in England is turning and the odds now momentarily against Britain exiting the EU later this week, the Dow shot up 270 points right out the gate and then spent the rest of the session gradually settling down to close 130 up.  But Thursday is still an eternity away and the slightest burp can easily send everything hurling in the other direction.  But at least the U.K.'s ETF is also seeing good news with the fund up four percent and at more than triple average volume.  Still, Thursday is an eternity away.  At 6.6 billion, volume was just a little below recent averages of 6.8 billion.

Markets | Mon Jun 20, 2016 4:35pm EDT

Wall Street ends higher as Britain seen staying in EU

NEW YORK | BY RODRIGO CAMPOS

REUTERS/BRENDAN MCDERMID

DJ:  17,804.87  +129.71     NAS: 4,837.21  +36.88      S&P: 2,083.25  +12.03

Wall Street rose on Monday, though indexes ended far from the highs of the day, in a relief advance after indications that British voters later this week will choose to remain in the European Union.

The day's gains were cut in more than half from the session highs, but contrasted with declines in six of the last seven sessions. The S&P 500 closed 0.6 percent higher after gaining as much as 1.4 percent, but the advance was still the largest in nearly a month.

Stocks fell sharply last week, partly on worries of what a British exit from the EU would mean for the global economy. The vote on whether to stay is scheduled for Thursday and the most recent polls showed a change in momentum to favor the 'remain' camp.

"The market is positioning for a 'remain' vote, so you see the fear and uncertainty trade unwinding right now," said Quincy Krosby, market strategist at Prudential Financial in Newark, New Jersey.

She said, however, that the reverse trade could be triggered by any sign the Brexit - or British exit from the EU - camp is gaining momentum.

"It is a long time between now and Thursday."

The Dow Jones industrial average rose 129.71 points, or 0.73 percent, to 17,804.87, the S&P 500 gained 12.03 points, or 0.58 percent, to 2,083.25 and the Nasdaq Composite added 36.88 points, or 0.77 percent, to 4,837.21.

The S&P 500 once more hit technical resistance at 2,100, a level that has seen clusters of sellers in the recent past. Despite the afternoon slide, all but one of the 10 industry groups of the S&P 500 ended in positive territory.

The iShares MSCI United Kingdom exchange-traded fund rose 4.0 percent in more than 3.5 times its average daily volume. The British pound gained 2.2 percent versus the U.S. dollar on its strongest day in 7-1/2 years.

U.S.-traded shares of JD.com rallied 4.6 percent to $21.06 after Walmart said it would sell its Chinese e-commerce business to JD.com and create a strategic alliance. Walmart shares gained 0.2 percent to $71.10.

Lending Club Corp gained 2.7 percent to $5.00 after Chinese billionaire Chen Tianqiao raised his stake in the online lending platform, following the recent ouster of founder and Chief Executive Renaud Laplanche.

NYSE advancing issues outnumbered decliners by a 3.47-to-1 ratio and on the Nasdaq a 2.79-to-1 ratio favored gainers.

About 6.6 billion shares were traded in U.S. exchanges, below the 6.83 billion daily average over the past 20 sessions.

The S&P 500 posted 35 new 52-week highs and 1 new low; the Nasdaq recorded 64 new highs and 35 new lows.