UPDATE 1-US STOCKS-Wall Street futures lower on Brexit concerns
* Early trading on Sunday evening shows weakness
* Some investors point to 'buying opportunity'
* Barron's says Goldman Sachs could rally 30 pct
* Friday's $2 trillion global equity selloff biggest ever -S&P (Adds investor quotes, updates market activity)
By Edward Krudy
NEW YORK, June 26 (Reuters) - U.S. stock index futures eased slightly in early trading on Sunday after Britain's vote to leave the European Union sparked a sharp sell-off in global markets on Friday, wiping out over $2 trillion from world equities.
Investors were blindsided by Thursday's vote, having bid up equity markets in the days leading up to it. U.S. stock indexes had been in striking distance of all-time highs, with some expecting a sharp rally to new highs in the coming days.
"The market's expensive so the risk is really high. There's a better time ahead for equities - it just isn't yet," said Steve Blumenthal, chief executive of CMG Capital Management Group Inc. in King of Prussia, Pennsylvania.
S&P 500 e-mini futures were down 0.5 percent. Dow Jones industrial average e-mini futures fell 0.6 percent and Nasdaq 100 e-mini futures fell 0.7 percent. Continuación...