The max pain move for SPX would be price making an abrupt low. The early rally producing multiple bear traps.
Then running the previous high. By a small margin. Not enough to please the "Blow-off" thesis but too much for the shorts to endure.
At this point, there'd be a general consensus the bear has failed. I'd expect also a suitable news narrative to support this (But I dont care about news).
The early dip would be enthusiastically bought up.
Bear warnings would be laughed off and mocks (Much like they were during the time the prime shorts were setting up late 2021).
All the way down people would remain in disbelief and the most popular target for SPX would be 6000 - 7000.
For a recent example of this to add context, see the BTC 69K high. Bears had no audience. 100K was the popular call. And the market had to decline more than the ininitial crash before there was a popular acceptance that people may have been rug pulled (And by then the low was being made on the terrible news, as it's prone to do).