As the S&P 500 index hit a new high for the 15th time in the year last Friday, reaching 5100 points for the first time in history, more records are being broken. A set of weekly level statistics shows that the S&P 500 index has achieved weekly gains in 16 out of the past 18 weeks. The last time this scene appeared could be traced back to March 1971, when the Bretton Woods system collapsed later that year.