The FOMC is likely to lower its guidance rate tomorrow. When the economy is expanding and stocks are near their highs (like now), this has been a net positive for equities.
Sentiment data is inconclusive, but a 3-5% decline wouldn't be unusual at this point, especially as the typically weak August-October period is now here.
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The rally since early June has carried SPX more than 10% higher in just two months. July will likely end with US equities higher for the 6th time in the past 7 months (table from alphatrends.net). Enlarge any chart by clicking on it.