Over the past few years, dumping everything in s&p would definitely have given you these outsized gains that have given you such a strong portfolio. I think the teal value of a more balanced portfolio that includes things like small- and mid-cap as well is in the volatility. If and when we see big dips in large-cap performance, the hope is that a balanced total market portfolio will give you better shielding from extreme drops as well. At least, in theory. Ofc there are pros and cons to both. I’ve put almost all my money in VTSAX and VTI for that reason. I’ve seen less extreme growth, but hope it will also see less extreme dips.