With Thursday’s 2% tumble, the S&P 500 finished July with a loss of almost 2.2%.

That could be enough to prompt investors to consider conservative sectors and the relevant exchange funds until U.S. stocks show the July swoon was no more than a mere bump on the road to more new highs.

Investors, both professional and retail, love sector ETFs. At least they did in the first half of this year when sector ETFs raked in $37.7 billion in new assets compared to $13.6 billion for broad U.S. market funds, Jackie Noblett reports for Ignites, citing Morningstar data. [Sector ETFs Balloon in Size]

However, the sector ETFs that are traditionally strong in August are showing signs of weakness. Making matters even trickier is that the two sector SPDR ETFs that historically the best in August are conservative, indicating that if weakness in these groups persists, that could be a bad sign for stocks.

Since 1999, the first full year in which the nine SPDRs traded, the Consumer Staples Select Sector SPDR (NYSEArca: XLP) is usually the best SPDR in August, posting an average gain in the eighth month of the year of less than 1%, according to CXO Advisory.