I guess nominal, because not having kept up with inflation would be the main source of it sucking badly. I think of it like this:

You lose to inflation badly with uninvested cash. You get close to keeping up with inflation with near zero risk vehicles (CD or high yield savings account). You hope to at least keep up with inflation with medium-low risk vehicles (S&P500 or similar funds). You roll the decide after that (leverage, timing, stock picking, etc.).