You don't need to "sail lang" to make money in stock market.
Just a portion like 30-50% buying during panic time will do the job and make you decent profit.
For eg. 100k, use 50K to buy during panic time, stock price can easily make you 30-100% afterwards when market recover time, which mean you can make a few ten k out of it.
Which is good enough.
Even Warren Buffett does not "sai lang". Berkshire is having significant high level of cash, in most time, even during market bull time, or bear time.
It is totally unwise to "sai lang" in whenever time.
Stock market is to make extra money using money.
Sai lang mean put all the money in risk.
Stock market is not everything in our life, don't need to sai lang, and potential make oneself miserable when unforseen event happened in stock market.
You don't know what can happen in stock market or your individual stock owned.