When you ask if the current U.S. stock market is a good environment to invest in in the medium to long term, my answer is no.

Currently, the market capitalization of the S&P 500 accounts for 50% of the world's GDP.

50% of all production activities produced in the world in a year are concentrated in the U.S. stock market.

There are a lot of variables here, and there may be more upside, but it's clear that it's not a good environment to invest in.