Options markets send cautiously bullish signal on U.S. stock rally

NEW YORK (Reuters) - As Wall Street stocks pause for breath following a blistering three-week surge, signals from the options market are suggesting that some investors believe the gains may endure. The Cboe Volatility Index , known as "Wall Street's fear gauge," ended below 40 on Tuesday for the first time since March 5, after rising as high as 82.69 during a sell-off that took the S&P 500 down as much as 34% from its peak. That 40 level is a significant one for some VIX watchers: The previous..