US STOCKS-S&P 500 futures rise after early signs Britain will stay in EU
* S&P 500 futures open higher after polls close
* Opinion poll puts "remain" campaign in lead
* Twilio Inc nearly doubles in welcome return of tech IPOs
* Indexes up: Dow 1.3 pct, S&P 1.3 pct, Nasdaq 1.6 pct (Updates to after close of polls in UK)
By Rodrigo Campos
June 23 (Reuters) - U.S. stock index futures opened higher in after hours trading on Thursday after polls closed in Britain with early signs that the "remain" campaign is leading in the country's EU membership referendum.
The gains added to a rally in stocks earlier on Wall Street as investors bet the United Kingdom would remain part of the European Union, potentially avoiding damage to European trand its consequences for the global economy.
The campaign to keep Britain in the European Union appeared to be ahead, according to polling firm YouGov which surveyed people about how they voted. The final official result is expected around 0600 GMT.
S&P 500 E-mini futures rose 0.5 percent and E-mini Dow Jones futures rose 0.52 percent. Continuación...