Watch what the smart money is doing. Warren Buffet's Berkshire Hathaway, AKA his investment firm, has about $250 billion in equities (stock) vs $340 billion in cash equivalents.
This is much more cash than he usually carries. Investors do this (sell stock, buy T bills) when they expect the stock market to fall substantially, and intend to buy stocks after they drop.
Buffett Indicator, which compares the total market capitalization of a country's stock market to its Gross Domestic Product (GDP). A high ratio, especially when exceeding 200%, is seen by Buffett as a sign that the market is overvalued, potentially signaling "playing with fire". Another "rule" associated with Buffett is his 90/10 strategy, which suggests allocating 90% of your portfolio to a low-cost S&P 500 index fund and 10% to short-term government bonds.
current Buffet indicator is 210% to 220%. Buffet is putting his money where his mouth is.