It's important to follow where the market is in relation to moving averages. There will be red days but the entire trend is still up. It's simply small corrections/profit taking that you see. Here's the SPY chart since March to help explain. Blue line is 50 day moving average.
Short term changes will NOT be linear. Short term changes also only matter to traders. If you aren't a short term trader, check the trend 1-2x a month and leave it be.
