The S&P has more or less been on an uphill trend for the past 3 months.
There is still a lot of cash on the sidelines, and there is still a lot of pessimism out there in regards to Covid and the general state of the economy, so this cash will be the ultimate backstop to the markets.
But this high only lasts for so long before you either have to pump up the patient again, or let the patient sober up.