No. of Recommendations: 5
In truth, the difference between SPY, RSP, and VXF (an extended market EFT) has been de minimus for the last twenty years or so. But over shorter (or simply different) periods they can vary more, in either direction.
https://stockcharts.com/freecharts/perf.php?SPY,RS...RSP's performance is basically indistinguishable from that of a S&P400 Mid-cap fund like IJH:
https://stockcharts.com/freecharts/perf.php?RSP,IJ...There are years-long periods when small/mid caps outperform, and vice versa. Combining SPY and VXF in some middling proportion would represent a hedge against that variance. You could also try to exploit the variance by trade them against each other, based on intermediate term momentum. Depends on your interest, and what your plan allows.
Baltassar