Adherents of technical analysis will be pleased to see the Nasdaq 100 Index rebounding from the first Fibonacci retracement level it encountered after a break from its yearlong uptrend. The tech-heavy gauge surged 4% on Tuesday, its biggest gain since November, as the rotation from growth to value shares violently reversed. The Nasdaq is not out of the woods yet though -- a failure to rise back above the uptrend would point the way to further downside in the gauge and another test of the support level that just held.