NEW YORK ( TheStreet) -- Today's buy-and-trade earnings previews cover nine companies; three from the aerospace sector, two from the medical sector and one each from the industrial product, retail-wholesale, transportation and utilities sectors.The ValuEngine valuation warning continues with 78.4% of all stocks being overvalued, 46.9% by 20% or more. Also, 15 of 16 sectors are overvalued, all by double-digit percentages, 11 by 21% to 27.4%. The aerospace sector is 23.3% overvalued with an underweight rating. 67.6% of the 74 stocks in this sector have sell or strong sell ratings. The industrial products sector is 22.9% overvalued with an underweight rating. 42.1% of the 347 stocks in this sector have sell or strong cell ratings. The medical sector is 22.0% overvalued with an equal-weight rating. 59.2% of the 784 stocks in this sector have hold ratings. The retail-wholesale sector is 27.4% overvalued with an overweight rating. 81.7% of the 349 stocks in this sector have buy or strong buy ratings.