No idea why that comment ended up dead. But anyway, in that case, one potential thing to invest in is a own company. If that is something you are interested in. Not now, but when the timing is right. Until then, leave the money where it is.

One other thing would be an extended travel / sabbatical. As soon as this is an option again, of course. Regarding the startup thing, this is what I did after two years. Less money (keep some funds for rainy days!), but with a house and family.