My advice would be think of it as gambling...because that's what it is. If it hurts to much to think about losing part of your initial investment..get out because that's a real risk. If you think it's going to hurt more because you see the stock market go up and wish you had stayed in...well stay in for the long haul where eventually the stock will bounce back.
Day traders can make a shit-tonne of cash one day and lose it all the next day.
No one really knows what's going to happen, as the stock market is not reflective of the economy or current social climate.
Yes, it is like gambling except you are the casino. If you are a small investors (between $10K and $10M), imagine that you own a small casino that has only a single roulette and nothing else, and, because of social distancing, only one person can play at the time. However, you can chose how everybody bet and how many people will play (with the only condition is the total amount of all bets placed). For each single person you prefer him to play several numbers or a colour instead of placing all his money on a single number: this way you, as a casino, will still have the same expected winning, but if you lose you will not lose that much. In investment terms, you want to invest in a portfolio of stocks to diversify. Next, you would like to have 100 people each betting $1000 instead of a single person betting $100,000: again, as a casino, you will have the same expected winning but much smaller probability to lose. In investment term, diversify across time.
So, basically, what you need to do is to invest in low-cost ETFs that track market index and "smooth:" you investment over time (do not buy in a single day). Similarly, when you sell, smooth your selling over time. And, of course, the longer you invest for (the longer you operate the casino), the more likely you will end up in a positive territory and the higher will be your average profit.
What you do not want to do is to try to "time the market" (i.e.,try to decide if it is the right time to buy or sell) or hand-pick the stocks. And, of course, your expected investment horizon should be at least 5 years.