Asset prices don't always go up. The downturns have lasted much longer than 5 years. So if you want relative certainty you'll have $X at a certain date then you

Asset prices don't always go up. The downturns have lasted much longer than 5 years. So if you want relative certainty you'll have $X at a certain date then you need to be in cash years beforehand. Otherwise you're gambling or have a backup source of cash.