I would typically agree with you but I think you are incorrect for a few reasons. (And I have seen this on other charts as well, so I am not just criticizing you)
In 1929, it took 5 months to go down from around July 1929. to Nov 1929. During that time, the market reversed/retraced 50% of the total bull market. Also, looking at the decline in 1929, it looks like it went straight down because the chart is squished/compacted (wrong word) together. So that drop looks exactly like we saw in Feb 2020 to Mar 2020 but in all reality the market didn't go straight down, There were alot of up and down movements. Then from the 50% mark in Nov 1929 it took another 5 months until the top in April 1930. After that peak, the market took another 26 months to decline to it's low in 1932.
In 2020, the market did a dramatic decline from Feb 2020 to March 2020. But the market only declined approximately 38% and that was only in about one month. Through April and part of May, it was a sideways kind of upward movement. So we still have about 1 month left of the decline to reach the 5 month mark and I think during this period it will reach 50% of the total bull market which started around 1995.
50% of the decline would take us to around 16,500 on the dow. We would reach that around June 20th. This would sort of make sense from a fundamental point of view as I believe we will have more fall out from corono until the economy/life gets more like it was before.
After June 20th (approx), the market will begin to go back up for approximately 5 more months until around the end of October 2020, just like it did from Nov 1929 until April 1930. Coincidentally, the end of October, 2020 is just around the US election. Following the peak of that upward movement, the market will take another 26 months to decline, just like it did from 1930 until 1932. We would reach the bottom around January of 2022. And then commodities will just go parabolically upwards.