你的抄底的现金哪里来的？囤在床垫下?

I am a middle class, I got salary and I have bills to pay, and I save for retirement by investing in stock market.  I don't have extra cash laying around when market bottoms out. 

That's why I need to cash out during market crash, to get cash to buy at the bottom.  Okay, maybe I should not sell 100%, but maybe 30%, 50% or whatever, my analysis on when to sell is still valid.  

If you have the luxury to have large cash income to buy at bottom without cashing out, kudos to you, but you didn't solve my problem.  You merely laughed at my problem.