The point is the upward wedge forming before that plunge was a better TA signal to go short once it crossed the rising trendline and you still could have caught a large piece of downside. The line you drew was not as obvious leading into it but the rising wedge was clearly forming.
The line he drew was, is, and always will be meaningless, imo.
+100 on the rising wedge you noted.
Here's one, hindsight, yes, but also foresight if Monday sees a bit more selling and a test of this weeks low:
The NQ trading range has a lower level that I've marked at the lowest daily close since the range started to develop. That level is 18063.50. Each time price has traded below that level intraday, the market has rallied hundreds of points.
IF NQ trades below 18063.50, I will be a buyer if it rallies back above that level.
I do not know if NQ will trade below, trade below and reverse, trade below and collapse, or gap up and never look back. But I do know that I have an excellent set up to trade if price trades below the lowest close and then comes back up through it.
Also, the day after the lowest close saw the lowest daily open since the range developed. That makes that level between 18063.50 and 18073.50 especially interesting from me. If price closes below that level, then I'd be looking for what happens next.