Best of all, shares of the company are historically cheap and producing a jaw-dropping annual yield. Investors can pick up Pfizer stock right now for an estimated 7 times forecast earnings for 2026. To boot, its nearly 8% dividend yield is nearing the highest level in the company's storied history.

Pointing to data showing run-ups in foreign purchases of U.S. stocks before the 1987 crash, the dot-com bubble in 2000, and the 2008 financial crisis, Ed Yardeni wrote in his eponymous research newsletter, "Their buying has a record of being a contrary indicator. They tend to be big buyers right before bear markets."