Despite the sharp intraday selloff in the major indexes from record highs Thursday, which has sent the CBOE Volatility Index VIX, +5.31% up 12% in afternoon trade, the Arms Index, which many use to measure buying or selling intensity, suggests investors remain relatively calm. On down days, the Arms tends to rise above 1.000, as the ratio of down volume to up volume rises relative to the ratio of declining stocks to rising stocks. But the NYSE Arms has slipped to 0.867 and the Nasdaq Arms has declined to 0.883, a sign that buyers on the dip have been slightly more aggressive than sellers. The Dow Jones Industrial Average DJIA, +0.39% the S&P 500 SPX, -0.10% and the Nasdaq Composite COMP, -0.63% were all up in record territory around noon ET before taking an afternoon dive. After paring some of the weakness, the Dow as up 30 points, the S&P 500 was down 0.3% and the Nasdaq was down 0.8% in recent trade.