The stock market always looks uncertain. There will always be bubbles.
https://en.wikipedia.org/wiki/Tulip_mania
The trick is to take advantage of adversity or high popularity. While trading futures, I would take advantage of disasters, such as drought or excess rain and hedge grain markets for example. When the stock market is down, the bond market is typically up. Even corporate bonds. If bonds are up, interest rates are down. There is always one aspect of the market that is stronger than others. For a while, gold mining companies were doing very well. For a while, companies that made equipment for oil drilling were doing well. And on and on. There is currently a redistribution of wealth going on. Mostly moving toward China. But countries are now trying to get accumulated debt off the books. The trick is to be diligent about greed. Earn money, then get out. Don't try to wait until the end. It surprises me what seems to be popular. For a while, I did very well with gambling companies, like Las Vegas Sands. Now, I'm enjoying Chinese online gaming companies, like
https://finance.yahoo.com/q?s=GA. I just have to figure out when to take profits and get out and quit being greedy. At times like this, one should look for companies that disribute dividends.
During the Great depression, alcohol and cosmetics did very well. People wanted to drown their woes and look good apparently.