NEW YORK ( TheStreet) -- The Dow transportation average set its latest all time high at 6,568.41 on May 20, two days below the Dow industrial average set its latest all time high at 15,542.40. In Record High Transports a Second Chance to Sell on May 8, all eight of the transportation stocks I have been tracking had sell ratings. Today six are rated sell and two rated hold. On May 8, 83.2% of all stocks in this sector were rated sell, and today 74.9% are rated sell, still negative enough to rate the sector "avoid-source of funds".Investors had that second chance to sell as Dow transports set another all-time high on May 20. In today's table of stocks, all eight are overvalued and seven of eight had double-digit gains of 10.1% to 47.2% over the last 12 months. The projected losses for the next 12 months range from down 4.4% and 8.6%. Caution flags are up as the 12 month trailing price-to-earnings ratios are becoming elevated between 14.1 and 27.1. All are above their 200-day simple moving averages which risks reversion to the mean.