you lose you might regret what you are doing. It's a way of taking risk and you do not need to put everything because the rule says you invest what you can afford.
So as they say, the biggest risk is not taking risk at all. For me both are good but investing is much better than saving. Though I read that we can invest atleast if we already have emergency fund. Because if we put our money in the bank, it is like 2% per annum. Inflation rate is around 4% so we already lose some of our money. in addition to that, the savings we have is taxable. So better to try taking a risk because 15% or up is really a good income.