假如100%投资在股票，你可能丢20-30%。
但如果50%在股票，你只丢10-15%。

Either way, it's not big deal unless you are very close to retirement. But for those who are close to retirement, it has long been advised that they reduce the exposure to risky assets and shift to riskless assets as the retirement approaches. so if they have heeded the advise, they should be OK mostly.