What if the starting point was the week of12/24/2018 when the index hit the low of 2346.58.
The Fibonacci projected the 100% high at 3336. The actual high was 3394, a 58-point difference or 1.7% shy. That's pretty close. Then, COVID-19 hit unexpectedly. What if there were no COVID-19? The market would have continued its usual course. The 261.8% projected high would have been 3954. The index hit 3950 on 2/16/2021. That's stunning. Of course, this is just a What-If.