What should investors do in a record-breaking environment for indexes? (1)

US indices are at record highs. Is this the cause of joy or concern? Rather for the second one.
Investors are interested in the future profitability of their investments, not the historical ones.
In a hurricane world, missile launches from North Korea and political uncertainty in Washington, the markets seem calm ... Even too calm. It seems as if nothing can get them out of their tracks.
Any decrease of 1 or 2% is rapidly recovering and is followed by new records. And so... The last time the indices drop by 2% and then fall with new 2% and new 2%.
Of course, when will the last time be is the biggest uncertainty in the equation.
However, in an environment where more and more experts are beginning to argue that there is still nothing terrible about US investors, they should definitely be afraid.