Since 2000, we've had 160 occasions in which there have been four consecutive rising days in the S&P 500 Index (SPY) such as we've had most recently.
Over the following three days, SPY has averaged a loss of -.37% (71 up, 89 down). By contrast, for the rest of the sample, the three-day return on SPY has been -.01% (1169 up, 1030 down).
It appears that some profit taking after a period of steady gains is normal. Indeed, returns have been negative from 1-5 days out following four days of consecutive gain.