NEW YORK ( TheStreet) -- The fundamentals of the stock market are not as positive as they were at the end of July when I began to write articles covering sector rotations and the SPDR exchange-traded funds that track key stock market sectors. A major factor in the weakening fundamentals was the yield on the 30-year Treasury bond, which rose from 2.439% on July 26 to 2.984% on Aug. 16. Because of this increase, fewer stocks are now undervalued. On July 30, my Web site, ValuEngine, showed that 67.1% of all stocks were undervalued. Today 58.7% of all stocks are undervalued. Technically, stocks as represented by the S&P 500 have become overbought on daily, weekly and monthly time horizons. On Tuesday, the S&P traded to a new 2012 high at 1426.68, its best level since May 2008. It was still well off the October 2007 high of 1576.06, however. Following are my "Buy and Trade" parameters for nine Select Sector SPDR ETFs. The basic materials sector was 16.0% undervalued at the end of July and is 7.6% undervalued today. My benchmark for this sector is the Materials Select Sector SPDR Fund ( XLB), and its daily chart profile shows overbought momentum. On July 31, I wrote "Trading the Undervalued Basic Materials Sector." XLB ($36.22) tested my monthly risky level at $36.61 on Tuesday where some profit-taking was justified. My annual pivot is $35.72, and my annual risky level is $37.93. The industrial product sector was 4.5% undervalued at the end of July and is 0.5% undervalued today. My benchmark for this sector is the Industrial Select Sector SPDR ( XLI), and its daily chart profile shows overbought momentum. On Aug. 13 I wrote "Trading Industrial and Transportation Stocks." XLI ($37.02) traded as high as $37.39 on Tuesday vs. my annual and quarterly risky levels at $37.74 and $38.02, respectively. I do not show any nearby value levels. The consumer discretionary sector was 6.6% undervalued at the end of July and is 0.6% overvalued today. My benchmark for this sector is the Consumer Discretionary Select Sector SPDR Fund ( XLY), and its daily chart profile also shows overbought momentum. On Aug. 14 I advised readers to "Book Profits in Consumer Discretionary Stocks." XLY ($45.18) is trading between my annual pivot at $43.17 and my monthly and quarterly risky levels at $47.52 and $50.12, respectively. My semiannual value level lags at $39.91.